#include<bits/stdc++.h>
using namespace std;
int n,m;
char a[1000010];
int tot=0;
int main(){
    freopen("type.in","r",stdin);
    freopen("type.out","w",stdout);
      cin>>n;
      for(int i=1;i<=n;i++){
          char x;
          char y;
          int s;
          cin>>x;
          if(x=='T'){
             cin>>y;
             a[++tot]=y; 
          }
          if(x=='U'){
              cin>>s;
              tot-=s;
          }
          if(x=='Q'){
              cin>>s;
              cout<<a[s]<<endl;
          }
      }
      return 0;
}