/*************************************
* author: marvinthang *
* created: 03.06.2023 16:23:06 *
*************************************/
#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define left ___left
#define right ___right
#define TIME (1.0 * clock() / CLOCKS_PER_SEC)
#define MASK(i) (1LL << (i))
#define BIT(x, i) ((x) >> (i) & 1)
#define __builtin_popcount __builtin_popcountll
#define ALL(v) (v).begin(), (v).end()
#define REP(i, n) for (int i = 0, _n = (n); i < _n; ++i)
#define REPD(i, n) for (int i = (n); i--; )
#define FOR(i, a, b) for (int i = (a), _b = (b); i < _b; ++i)
#define FORD(i, b, a) for (int i = (b), _a = (a); --i >= _a; )
#define FORE(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define FORDE(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define scan_op(...) istream & operator >> (istream &in, __VA_ARGS__ &u)
#define print_op(...) ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
#include "debug.h"
#else
#define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define DB(...) 23
#define db(...) 23
#define debug(...) 23
#endif
template <class U, class V> scan_op(pair <U, V>) { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>) { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>) { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")"; else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
// end of template
const int MAX = 1e6 + 6;
const int LOG = 20;
int N, M, depth[MAX], anc[MAX][LOG], pos[MAX];
char letters[MAX];
void Init() {}
void TypeLetter(char L) {
letters[++N] = L;
depth[N] = depth[pos[M]] + 1;
anc[N][0] = pos[M];
FOR(i, 1, LOG) anc[N][i] = anc[anc[N][i - 1]][i - 1];
pos[++M] = N;
}
void UndoCommands(int U) {
pos[M + 1] = pos[M - U];
++M;
}
char GetLetter(int P) {
int u = pos[M];
REPD(i, LOG) if (depth[anc[u][i]] > P) u = anc[u][i];
return letters[u];
}
#ifdef LOCAL
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>
#define inbuf_len 1 << 16
#define outbuf_len 1 << 16
void Init();
void TypeLetter(char L);
void UndoCommands(int U);
char GetLetter(int P);
int main() {
file("scrivener");
Init();
int cmd_num;
int tmp = scanf("%d", &cmd_num);
assert(tmp == 1);
int i;
for (i = 0; i < cmd_num; i++) {
char cmd;
tmp = scanf(" %c", &cmd);
assert(tmp == 1);
if (cmd == 'T') {
char letter;
tmp = scanf(" %c", &letter);
assert(tmp == 1);
TypeLetter(letter);
}
else if (cmd == 'U') {
int number;
tmp = scanf("%d", &number);
assert(tmp == 1);
UndoCommands(number);
}
else if (cmd == 'P') {
int index;
char letter;
tmp = scanf("%d", &index);
assert(tmp == 1);
letter = GetLetter(index);
printf("%c\n", letter);
}
}
puts("Let's test for cheating!!");
return 0;
}
#endif
