#include <stdio.h>
#include <string.h>

void skipcomment(void);
void skipstring(void);
int getnext(void);
void readline(void);
int matchbracket(char);
int addbracket(char);
int openbrackets(int);
void cleanstack(void);

#define MAXLINE 101
#define START 1
#define COMMENT_START '\'
#define NEW_LINE '\n'
#define STRING '"'
#define END 2
#define RUNNING 1

int main(){

    while(c=getnext() != EOF)
        switch(c){
            case STRING:
                skipstring();
                break;

            case COMMENT_START:
                if((c=getnext()) == '*')
                    skipcomment();
                break;

            case '{': case '(': case '[':
                addbracket(c);
                break;

            case '}': case ')': case ']':
                if(!bracketmatch(c))
                    printerr();
                break;

            case NEW_LINE:
                if(openbrackets(RUNNING))
                    printerr();
                cleanstack();
                break;
        }
    if(openbrackets(END))
        printerr();
}



char line[MAXLINE+1];
int ind = START;


char getnext(){
    if(ind==START || ind>MAXLINE || line[ind] == '\0')
        readline();
    return line[ind++];
}

void readline(){
    for(ind = START ; ind <= MAXLINE && (line[ind] = getchar()) != '\n' && line[ind] != EOF ; ind++)
        ;
    line[++ind] = '\0';
    ind = START;
}

void skipstring(){
    char c;
    while((c=getnext()) != '"')
        if(c=='\\' && (c=getnext()) == '"')
            continue;
}

void skipcomment(){
    char c;
    while((c=getnext()))
        if(c == '*'){
            while(c == '*')     /* skip all asterisks */
                c = getnext();
            if(c == '/')        /* if closed with an '/' thats the end of the comment */
                return;
        }
}

char brackstack[MAXLINE];
int k = START;
int c_bracket = 0;      /* holds the amount of curly/round/square brackets */


void addbracket(char brack){
    if(brack == '[')
        brackstack[k++] = ']';
    else if(brack == '(')
        brackstack[k++] = ')';
    else
        c_bracket++;
}

int matchbracket(char brack){
    if(k<START)
        return 0;
    if(brack == ']' || brack == ')')
        return brack == brackstack[k]?k--:FALSE;
    else if(c_bracket<=0)
        return 0;
    else {
        c_bracket++;
        return 1;
    }
}

void cleanstack(){
    k = START;
}

int openbrackets(int state){
    if(state == RUNNING)
        return k != START;
    else if(state == END)
        return k != START && c_bracket==0;
}