#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define REP(i,j,k) for(int i = j ; i < k ; ++i)
#define RREP(i,j,k) for(int i = j ; i >=k ; --i)
#define A first
#define B second
#define mp make_pair
#define pb emplace_back
#define PII pair<int , int>
#define MEM(i,j) memset(i , j , sizeof i)
#define ALL(i) i.begin() , i.end()
#define DBGG(i,j) cout << i << " " << j << endl
#define DB4(i,j,k,l) cout << i << " " << j << " " << k << " " << l << endl
#define IOS cin.tie(0) , cout.sync_with_stdio(0)
#define endl "\n"
///------------------------------------------------------------
#define MAX 1000000
#define INF 0x3f3f3f3f
crope s[MAX];
int pos;
void Init(){
}
void TypeLetter(char c){
pos ++;
s[pos] = s[pos - 1];
s[pos].push_back(c);
}
void UndoCommands(int k){
pos ++;
s[pos] = s[pos - k - 1];
}
char GetLetter(int idx){
return s[pos][idx];
}
// int32_t main(){
// IOS;
//
// return 0;
// }
