/*
Task : combo
Author : Phumipat C. [MAGCARI]
Language: C++
Created : 17 May 2021 [12:41]
Algo :
Status :
*/
#include<bits/stdc++.h>
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x),end(x)
#define allst(x,y) (x).begin()+y,(x).end()
#define rmdup(x) (x).resize(unique((x).begin(),(x).end())-(x).begin())
#define sz(x) (int)(x).size()
#define decp(x) fixed << setprecision(x)
#define MOD (LL )(1e9+7)
using namespace std;
using LL = long long;
using PII = pair<int ,int >;
using PLL = pair<long long ,long long >;
const int dir4[2][4] = {{1,-1,0,0},{0,0,1,-1}};
const int dir8[2][8] = {{-1,-1,-1,0,1,1,1,0},{-1,0,1,1,-1,0,1,-1}};
LL modN(LL a,LL b,LL c = MOD){
if(b == 0) return 1;
if(b == 1) return a%c;
LL now = modN(a,b/2,c);
if(b&1) return (((now*now)%c)*(a%c))%c;
else return (now*now)%c;
}
#include "combo.h"
std::string guess_sequence(int N) {
vector<char > c(3);
vector<char >::iterator it;
c = {'A','B','X'};
char last = 'Y';
it = c.begin();
int ret = 0;
string now;
now.push_back('0');
for(auto x:c){
now.back() = x;
ret = press(now);
if(ret){
c.erase(it);
break;
}
it++;
}
if(!ret) now.back() = last;
else c.push_back('Y');
rep(i,2,N){
string ask = now + c[0] + now + c[1]+c[0] + now + c[1]+c[1] + now + c[1]+c[2];
ret = press(ask);
if(ret == i) now.push_back(c[0]);
else if(ret == i+1) now.push_back(c[1]);
else now.push_back(c[2]);
}
last = c.back();
c.pop_back();
now.push_back('0');
for(auto x:c){
now.back() = x;
ret = press(now);
if(ret == N) return now;
}
now.back() = last;
// cout << now << '\n';
return now;
}
//grader.cpp
// namespace {
// constexpr int MAX_N = 2000;
// constexpr int MAX_NUM_MOVES = 8000;
// int N;
// std::string S;
// int num_moves;
// void wrong_answer(const char *MSG) {
// printf("Wrong Answer: %s\n", MSG);
// exit(0);
// }
// } // namespace
// int press(std::string p) {
// if (++num_moves > MAX_NUM_MOVES) {
// wrong_answer("too many moves");
// }
// int len = p.length();
// if (len > 4 * N) {
// wrong_answer("invalid press");
// }
// for (int i = 0; i < len; ++i) {
// if (p[i] != 'A' && p[i] != 'B' && p[i] != 'X' && p[i] != 'Y') {
// wrong_answer("invalid press");
// }
// }
// int coins = 0;
// for (int i = 0, j = 0; i < len; ++i) {
// if (j < N && S[j] == p[i]) {
// ++j;
// } else if (S[0] == p[i]) {
// j = 1;
// } else {
// j = 0;
// }
// coins = std::max(coins, j);
// }
// return coins;
// }
// int main() {
// char buffer[MAX_N + 1];
// if (scanf("%s", buffer) != 1) {
// fprintf(stderr, "Error while reading input\n");
// exit(1);
// }
// S = buffer;
// N = S.length();
// num_moves = 0;
// std::string answer = guess_sequence(N);
// if (answer != S) {
// wrong_answer("wrong guess");
// exit(0);
// }
// printf("Accepted: %d\n", num_moves);
// return 0;
// }
