#include <bits/stdc++.h>
using namespace std;
struct state{
  int curl;
  char curc;
  state* par;
};
vector<state> states;
state cs;
void Init() {
  cs.curl=-1;
  cs.curc=' ';
  cs.par=nullptr;
  states.push_back(cs);
}
void TypeLetter(char L) {
  state x;
  x.curl=cs.curl+1;
  x.curc=L;
  x.par=&states[states.size()-1];
  states.push_back(x);
  cs=x;
}
void UndoCommands(int U) {
  state x;
  x.curl=states[states.size()-U-1].curl;
  x.curc=states[states.size()-U-1].curc;
  x.par=&states[states.size()-U-1];
  states.push_back(x);
  cs=states.back();
  
}
char GetLetter(int P) {
 state tmp=cs;
 while(tmp.curl!=P)tmp=*tmp.par;
 return tmp.curc;
}
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict  | Execution time | Memory | Grader output | 
|---|
| Fetching results... |