#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define INF 1000000000
#define LINF 10000000000000000LL
#define pb push_back
#define all(x) x.begin(), x.end()
#define len(s) (int)s.size()
#define test_case { int t; cin>>t; while(t--)solve(); }
#define single_case solve();
#define line cerr<<"----------"<<endl;
#define ios { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cerr.tie(NULL); }
#define mod 1000000007LL
const int N = 1e6 + 50;
int up[N][21];
int cvor[N];
int ind;
int ind2;
char s[N];
int dub[N];
void Init()
{
}
void TypeLetter(char l)
{
ind++;
ind2++;
cvor[ind2] = ind;
s[ind] = l;
up[ind][0] = cvor[ind2-1];
dub[ind] = dub[cvor[ind2-1]] + 1;
for(int i = 1;i<=20;i++) up[ind][i] = up[up[ind][i-1]][i-1];
}
void UndoCommands(int u)
{
ind2++;
cvor[ind2] = cvor[ind2-1-u];
}
char GetLetter(int p)
{
p++;
int x = cvor[ind2];
for(int i = 20;i>=0;i--)
{
int w = up[x][i];
if(dub[w]<p) continue;
x = w;
}
return s[x];
}
