#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<setjmp.h>
#include<ctype.h>
#include<gc.h>
#include<unicode/ustdio.h>
#include<unicode/ustring.h>
#define free

typedef UChar UC;
typedef UC*US;
typedef char C;
typedef C*S;
#define CUS const US
typedef S*SS;
typedef int I;
typedef long long L;
typedef double D;
typedef size_t Z;
typedef void U;
typedef U*P;
typedef P*PS;
typedef enum{N,Y}B;
#define R return
#define BK break
#define SW(e) switch(e) {
#define CS(e) case e:
#define DO(v) for(I v=0;;){
#define EL default:
#define ES }else{
#define EIF(e) }else if(e){
#define WH(e) while(e){
#define WY while(Y){
#define NL() putchar('\n')

jmp_buf J;
L ln, cl;
B ir=N;

US erh;
#define sh(s)erh=u8_strdup(s); //set help
#define eh()erh=u8_strconv_from_locale(""); //erase help
U e(S s){fprintf(stderr,"|%s\n",s);if(u8_strlen(erh)>0){fprintf(stderr,"|\t%s\n",erh);free(erh);eh();}if(ir)longjmp(J,1);else exit(1);} //report error

#define XE  e("syntax error")
#define TE  e("type error")
#define PE  e("parse error")
#define SPE e("spelling error")
#define DE  e("domain error")
#define SE  e("stack error")
#define YE  e("syntax error")
#define ME  e("memory error")
#define IE  e("arity error")
#define BE  e("balance error")

P al(Z z){P r;if(!(r=GC_MALLOC(z)))ME;R r;} //alloc
P als(Z z){R al(sizeof(C)*(z+1));} //alloc str
P alu(Z z){R al(sizeof(UC)*(z+1));} //alloc ustr
#define rl(p,z)if(!(p=GC_REALLOC(p,z)))ME; //realloc

#define FR(e) // nope
#define MC(s,d,c) memcpy(s,d,c)
#define SL(e) strlen(e)
#define USL(e) u8_strlen(e)
#define SZ(e) sizeof(e)
#define NUL(e) memcpy(e,0,SZ(e))
#define NLU(e,s) memcpy(e,0,s)
#define NLS(e) e[0]=0
#define MZ 2048

US rel(){Z z;S r=als(MZ);if(!fgets(r,MZ,stdin)){if(feof(stdin)){*r=0;R u8_strconv_from_locale(r);}else DE;}z=strlen(r);if(r[z-1]=='\n')r[z-1]=0;if(z>1&&r[z-2]=='\r')r[z-2]=0;R u8_strconv_from_locale(r);} //read line

typedef struct{PS s;Z t,z;}AE; // stack element
typedef AE*A; // stack
A ma(Z z){A s=al(sizeof(AE));s->s=al(z*sizeof(P));
          s->t=0;s->z=z;R s;} //make stack
U u(A s,P v){if(v==NULL)R;if(s->t+1>s->z)SE;s->s[s->t++]=v;} //put
P t(A s){if(s->t==0)SE;R s->s[--s->t];} //take
P sk(A s){if(s->t==0)SE;R s->s[s->t-1];} //seek
Z l(A s){R s->t;} //len
U fa(A s){FR(s->s);FR(s);} //free stack

A Ma=0; //main stack
typedef enum{TD,TS,TL,TC,TP,TV}T; // type
typedef struct VB VB;typedef VB* V;
typedef V(*DYAD)(V,V);
typedef V(*MONAD)(V);
V mvv(UC o);
struct VB{T t;union{D d;struct{UC o;I a;DYAD d;MONAD m;}v;struct{US s;Z z;}s;A l;struct{V x,y;}p;};};typedef VB*V; // value

US tos(V m,B q){
  Z z;I i;US b,t;Z lx;US tx;
  SW(m->t)
  CS(TV)b=alu(2);b[0]=m->v.o;b[1]=0;BK;
  CS(TD)b=alu(MZ);sprintf(b,"%.15g",m->d);if(b[0]=='-')b[0]='_';BK;
  CS(TS)b=alu(m->s.z+(q?4:0));if(q)b[0]='\'';MC(b+1,m->s.s,m->s.z);if(q)b[u8_strlen(b)]='\'';b[u8_strlen(b)]=0;BK;
  CS(TL)b=alu(1);b[0]='[';z=1;for(i=0;i<l(m->l);++i){Z l;if(i){rl(b,z+1);b[z++]=' ';}t=tos(m->l->s[i],Y);l=u8_strlen(t);rl(b,z+l);MC(b+z,t,l);z+=l;FR(t);}rl(b,z+2);b[z]=']';b[z+1]=0;BK;
  CS(TC)b=alu(m->s.z+3);b[0]='{';MC(b+1,m->s.s,m->s.z);MC(b+1+m->s.z,"}",2);BK;
  CS(TP)t=tos(m->p.x,Y);tx=tos(m->p.x,Y);z=u8_strlen(t);lx=u8_strlen(tx);b=al(z+lx+5);sprintf(b,"(%s: %s)",t,tx);FR(t);FR(tx);BK;
  EL DE;}
  R b;
} //value to str
V mv(){R al(SZ(VB));} //make value
V mvd(D d){V m=mv();m->t=TD;m->d=d;R m;} //make number value
V mcv(US s,Z z){V m=mv();m->t=TC;m->s.s=u8_strdup(s);
                m->s.z=z;R m;} //make code value
V mvcn(US s,Z z){V m=mv();m->t=TC;
                 m->s.s=s;m->s.z=z;R m;} //make code (non-copy) value
V mvs(US s){V m=mv();m->t=TS;m->s.s=u8_strdup(s);
            m->s.z=u8_strlen(s);R m;} //make str value
V msc(UC c){UC b[]={c,0};R mvs(b);} //make str value from char
V mvl(A l){V m=mv();m->t=TL;m->l=l;R m;} //make list value
V mvp(V x,V y){V m=mv();m->t=TP;
              m->p.x=x;m->p.y=y;R m;} //make pair value
Z ll(V s){R l(s->l);} //list len
V lat(V s,Z i){R s->l->s[i];} //list at
U frm(V m){
  SW(m->t)
  CS(TS)CS(TC)FR(m->s.s);BK;
  CS(TL)while(l(m->l))frm(t(m->l));fa(m->l);BK;
  CS(TD)CS(TV)BK;
  CS(TP)frm(m->p.x);frm(m->p.y);BK;
  }FR(m);
} //free value
V d(V);V da(V m){A s=ma(MZ);Z i=0;for(i=0;i<l(m->l);++i)u(s,d(m->l->s[i]));R mvl(s);} //dup array
V d(V m){
  Z z;S s;
  SW(m->t)
  CS(TV)R mvv(m->v.o);
  CS(TC)R mcv(m->s.s,m->s.z);
  CS(TS)R mvs(m->s.s);
  CS(TD)R mvd(m->d);
  CS(TL)R da(m);BK;
  CS(TP)R mvp(d(m->p.x),d(m->p.y));
  EL DE;}R 0;
} //dup val
B eq(V a,V b){
  if(a->t!=b->t)R N;
  SW(a->t)
  CS(TV)R a->v.a==b->v.a&&a->v.o==b->v.o;
  CS(TS)CS(TC)R a->s.z!=b->s.z?0:memcmp(a->s.s,b->s.s,a->s.z)==0;
  CS(TD)R a->d==b->d;
  CS(TP)R eq(a->p.x,b->p.x)&&eq(a->p.y,b->p.y);
  EL TE;}R N;
} //equal
B tr(V m){
  SW(m->t)
  CS(TV)R Y;
  CS(TS)CS(TC)R m->s.z!=0;
  CS(TL)R l(m->l)!=0;
  CS(TP)R tr(m->p.x)&&tr(m->p.y);
  CS(TD)R m->d!=0;
  }
} //truthy
US ucts(UC c){US b=alu(2);b[0]=c;b[1]=0;
              R b;} //char to ustr

typedef struct _VR{UC s[256];V v;struct _VR *n;}ENV; //environment
ENV*v[512]; //main environment

L h(US s){US q;L k;
         for(k=0,q=s;*q;q++)k=(k<<3)^*q;
         R k%512;} //hash
V fe(US s){ENV*p;L k;k=h(s);
  for(p=v[k];p;p=p->n)if(u8_strcmp(s,p->s)==0)R p->v;
  R 0;} //find entry
U be(US s,V x){ENV*p;L k;k=h(s);
  for(p=v[k];p;p=p->n)if(!u8_strcmp(s,p->s)){p->v=x;R;}
  p=al(sizeof(ENV));u8_strncpy(p->s,s,255);p->s[255]=0;
  p->v=x;p->n=v[k];v[k]=p;} //bind entry
D pd(S s){S err;D r=strtod(s,&err);
  if(r==0&&!isspace(*err)&&s==err)PE;
  R r;} //parse number
I r(US s,B q);
US tra(US s,B inl);
#define ud(s,d)u(s,mvd(d)) //put number
#define us(s,r)u(s,mvs(r))
typedef enum{SN,SR,SD,SC,SL,SV}E; //state (none, string, number, code, list, var)
#define IS(s) if(st == s) {
#define NO(s) if(st != s) {
#define NOT(s) (st != s)
#define OR(s) || st == s
#define SI(s) st = s

#define D(n)V D##n(V x,V y)
#define M(n)V M##n(V x)

US Dtos(UC o,V x,V y){US b=alu(1024);u8_snprintf(b,1024,"%U%U%c",tos(x,Y),tos(y,Y),o);
               R b;} //dyad to string
US Mtos(UC o,V x){US b=alu(1024);u8_snprintf(b,1024,"%U%c",tos(x,Y),o);R b;} //monad to string
#define TED(o)sh(Dtos(o,x,y));TE;
#define TEM(o)sh(Mtos(o,x));TE;
#define _tcD(o,ty,x,y)if(x->t!=ty||y->t!=ty){TED(o);}
#define tcD(o,ty)_tcD(o,ty,x,y)
#define tcDV(o,tyx,tyy)if(x->t!=tyx||y->t!=tyy){TED(o);}
#define tcM(o,ty)if(x->t!=ty){TEM(o);}
D(plus){tcD('+',TD);R mvd(x->d+y->d);}
D(minus){tcD('-',TD);R mvd(x->d-y->d);}
D(star){tcD('*',TD);R mvd(x->d*y->d);}

V apD(DYAD f,V x,V y);
D(reduce){tcDV('/',TV,TL);if(x->v.a!=2){sh(Dtos('/',x,y));IE;}if(ll(y)<1){sh(Dtos('/',x,y));e("length error");}if(ll(y)==1)R lat(y,0);V b;Z i;b=t(y->l);
for(i=0;i<ll(y);i++){b=apD(x->v.d,b,lat(y,i));}R b;}

M(apply){tcM('@',TC);L _ln,_cl;_ln=ln;_cl=cl;r(x->s.s,N);ln=_ln;cl=_cl;R NULL;}
M(negate){tcM('_',TD);R mvd(-x->d);}

V mvv(UC o){V m=mv();m->t=TV;m->v.o=o;
            SW(o)
            CS('+')m->v.a=2;m->v.d=Dplus;BK;
            CS('-')m->v.a=2;m->v.d=Dminus;BK;
            CS('*')m->v.a=2;m->v.d=Dstar;BK;
            CS('_')m->v.a=1;m->v.m=Mnegate;BK;
            EL sh(ucts(o));PE;}R m;} //make ref

V apD(DYAD f,V x,V y){V s;I i;
if(x->t==TL&&y->t==TL){if(ll(x)!=ll(y))e("rank error");s=mvl(ma(MZ));for(i=0;i<ll(x);i++){u(s->l,apD(f,lat(x,i),lat(y,i)));}R s;}
if(x->t==TL){s=mvl(ma(MZ));for(i=0;i<ll(x);i++){u(s->l,apD(f,lat(x,i),y));}R s;}
if(y->t==TL){s=mvl(ma(MZ));for(i=0;i<ll(y);i++){u(s->l,apD(f,x,lat(y,i)));}R s;}
R f(x,y);} //apply dyad
V apM(MONAD f,V x){V s;I i;
if(x->t==TL){s=mvl(ma(MZ));for(i=0;i<ll(x);i++){u(s->l,apM(f,lat(x,i)));}R s;}
R f(x);} //apply monad
#define mAD(o)if(l(la)<2){if(l(la)==1){sh(Mtos(c,t(la)));}else{sh(ucts(c));}IE;}y=t(la);x=t(la);u(la,D##o(x,y)); //make atomic dyad
#define mD(o)if(l(la)<2){if(l(la)==1){sh(Mtos(c,t(la)));}else{sh(ucts(c));}IE;}y=t(la);x=t(la);u(la,apD(D##o,x,y)); //make dyad
#define mM(o)if(l(la)<1){sh(ucts(c));IE;}x=t(la);u(la,apM(M##o,x)); //make monad
#define PRELOG if(!Ma){Ma=ma(MZ);u(Ma,ma(MZ*2));}
#define PROLOG PRELOG;ln=1;cl=0;
#define ul(s)u8_strconv_from_locale(s)
I r(US s,B q) {
  PROLOG;L _ln,_cl;
  A la=sk(Ma);E st=SN;UC c;V x,y;US nb;Z nr,red;L bl,cbl;B ru=N;
  DO(i)if(ru)BK;cl++;c=s[i++];
    if((isdigit(c)||c=='.')&&NOT(SR)&&NOT(SL)&&NOT(SC)){NO(SD)SI(SD);red=256;nr=0;nb=alu(red);NLS(nb);}
                           nr++;if(nr>=red){red*=2;rl(nb,red);}u8_strncat(nb,&c,1);}
    if(isalpha(c)&&NOT(SR)&&NOT(SL)&&NOT(SC)&&NOT(SD)){NO(SV)SI(SV);nb=alu(256);nr=0;NLS(nb);}
                            if(nr>=255)ME;u8_strncat(nb,&c,1);}
    IS(SV)if(!isalpha(c)){SI(SN);if(c==':'){x=t(la);be(nb,x);ES x=fe(nb);if(!x){sh(nb);e("name error");}u(la,d(x));}if(c!=':'){cl--;i--;}}}
    else IS(SC)if(cbl<0||c==0)BE;if(nr>=red){red*=2;rl(nb,red);}if(c=='{')cbl++;if(c=='}')cbl--;if(cbl==0){SI(SN);u(la,mcv(nb,u8_strlen(nb)));ES nr++;u8_strncat(nb,&c,1);}}
    else IS(SL)if(bl<0||c==0)BE;if(nr>=red){red*=2;rl(nb,red);}if(c=='[')bl++;if(c==']')bl--;if(bl==0){SI(SN);u(Ma,ma(MZ));_ln=ln;_cl=cl;r(nb,N);ln=_ln;cl=_cl;u(la,mvl(t(Ma)));ES nr++;u8_strncat(nb,&c,1);}}
    else IS(SR)if(c==0)BE;if(c=='\''){SI(SN);nb[nr+1]=0;us(la,nb);}else{nr++;if(nr>=red){red*=2;rl(nb,red);}u8_strncat(nb,&c,1);}}
    else IS(SD)if(!isdigit(c)&&c!='.'){SI(SN);nr=0;ud(la,pd(u8_strconv_to_locale(nb)));FR(nb);cl--;i--;}
    ES SW(c)
       CS('\'')red=128;nb=alu(red);nr=0;SI(SR);BK;
       CS('+')mD(plus);BK;
       CS('-')mD(minus);BK;
       CS('*')mD(star);BK;
       CS('/')mAD(reduce);BK;
       CS(':')if(!ispunct(s[i])){sh(ul(":"));PE;}u(la,mvv(s[i]));cl++;i++;BK;
       CS('@')mM(apply);BK;
       CS('_')mM(negate);BK;
       CS('[')red=256;nr=0;bl=1;nb=alu(red);SI(SL);BK;
       CS('{')red=256;nr=0;cbl=1;nb=alu(red);SI(SC);BK;
       CS(' ')CS('\t')CS('\r')BK;
       CS('\n')ln++;BK;
       CS(0)IS(SR OR(SC)OR(SL))BE;}IS(SV)e("syntax error");}ru=Y;BK;
       EL sh(ucts(c));SPE;BK;}}
  }if(ir&&q&&l(la))printf("%s\n",tos(sk(la),Y));R 0;} //run

U il() {US in;printf("sara\t\\\\ to exit\n\n");ir=Y;WH(Y)putchar('\t');if(!setjmp(J)){in=rel();if(u8_strcmp(in,ul("\\\\"))==0)exit(0);r(in,Y);}if(Ma){A la=sk(Ma);while(l(la))frm(t(la));fa(la);fa(Ma);Ma=0;}}} //interactive loop
I main(I ac,SS a){GC_INIT();PROLOG;eh();il();R 0;}