#include<iostream>
#include<cstdio>
#include<algorithm>
#include<set>
#include<map>
#include<queue>
#include<cassert>
#define PB push_back
#define MP make_pair
#define sz(v) (in((v).size()))
#define forn(i,n) for(in i=0;i<(n);++i)
#define forv(i,v) forn(i,sz(v))
#define fors(i,s) for(auto i=(s).begin();i!=(s).end();++i)
#define all(v) (v).begin(),(v).end()
using namespace std;
typedef long long in;
typedef vector<in> VI;
typedef vector<VI> VVI;
VI opr;
VVI nbs;
VI undl,undr;
void mkclr(){
  opr.clear();
  in u=0;
  in prv=-1;
  do{
    opr.PB(u);
    forv(i,nbs[u]){
      if(nbs[u][i]!=prv){
    prv=u;
    u=nbs[u][i];
    break;
      }
    }
  }while(u!=sz(nbs)-1);
  opr.PB(u);
  undl.clear();
  undr.clear();
}
const in slm=300;
in gg(in a){
  for(in i=sz(undl)-1;i>=0;--i){
    if(a>=undl[i] && a<=undr[i])
      a=(undl[i]+undr[i]-a);
  }
  return opr[a];
}
in fnb(in a, in b){
  forv(i,nbs[a])
    if(nbs[a][i]==b)
      return i;
  assert(0);
  return 0;
}
void doop(in l, in r){
  if(sz(undl)>=slm)
    mkclr();
  in c1=gg(l);
  in c2=gg(l+1);
  in d1=gg(r);
  in d2=gg(r-1);
  in nleft=!fnb(c1,c2);
  in nright=!fnb(d1,d2);
  nbs[nbs[c1][nleft]][fnb(nbs[c1][nleft],c1)]=d1;
  nbs[nbs[d1][nright]][fnb(nbs[d1][nright],d1)]=c1;
  swap(nbs[c1][nleft],nbs[d1][nright]);
  undl.PB(l);
  undr.PB(r);
}
string rst;
VI epr;
queue<in> tcg;
VI ts;
void mkrs(in k){
  forv(i,rst)
    if(rst[i]!='?')
      tcg.push(i);
  while(!tcg.empty()){
    in u=tcg.front();
    tcg.pop();
    if(rst[epr[u]]!=rst[u]){
      if(rst[epr[u]]!='?'){
    cout<<"Bad Luck Allen\n";
    return;
      }
      rst[epr[u]]=rst[u];
      tcg.push(epr[u]);
    }
  }
  const in alsz=26;
  forv(i,rst){
    if(rst[i]!='?')
      continue;
    ts.PB(i);
    rst[i]='x';
    tcg.push(i);
    while(!tcg.empty()){
      in u=tcg.front();
      tcg.pop();
      if(rst[epr[u]]!=rst[u]){
    if(rst[epr[u]]!='?'){
      cout<<"Bad Luck Allen\n";
      return;
    }
    rst[epr[u]]=rst[u];
    tcg.push(epr[u]);
      }
    }
  }
  for(in i=sz(ts)-1;i>=0;--i){
    rst[ts[i]]='a'+(k%alsz);
    k/=alsz;
    tcg.push(ts[i]);
    while(!tcg.empty()){
      in u=tcg.front();
      tcg.pop();
      if(rst[epr[u]]!=rst[u]){
    if(rst[epr[u]]!='x'){
      cout<<"Bad Luck Allen\n";
      return;
    }
    rst[epr[u]]=rst[u];
    tcg.push(epr[u]);
      }
    }
  }
  if(k)
    cout<<"Bad Luck Allen\n";
  else
    cout<<rst<<"\n";
}
int main(){
  ios::sync_with_stdio(0);
  cin.tie(0);
  in n,m,k;
  cin>>n>>m>>k;
  opr=VI(n+2);
  forv(i,opr)
    opr[i]=i;
  nbs.resize(n+2);
  nbs[0]={1};
  nbs[n+1]={n};
  for(in i=1;i<=n;i++)
    nbs[i]={i-1,i+1};
  cin>>rst;
  in l,r;
  forn(i,m){
    cin>>l>>r;
    if(l!=r)
      doop(l,r);
  }
  mkclr();
  for(in i=1;i<=n;++i)
    epr.PB(opr[i]-1);
  mkrs(k-1);
  return 0;
}