// Success consists of going from failure to failure without loss of enthusiasm
#include <bits/stdc++.h>
using namespace std;
#define nl '\n'
#define sz(x) int(x.size())
using T = pair<int, string>;
#define f first
#define s second
#define mp make_pair
int query(string str);
string guess(int N, int S) {
priority_queue<T, vector<T>, greater<T>> q;
for(char c = 'a'; c < 'a' + S; c++) {
int amt = query(string(N, c));
q.push(mp(amt, string(amt, c)));
}
auto merge = [&](string a, string b) {
string c = "";
int j = 0; for(int i = 0; i < sz(a); i++) {
while(j < sz(b)) {
string d = c + b[j] + a.substr(i);
int left = N - sz(d); d += string(left, a.back());
int len = query(d);
if (len != N - left) break;
c += b[j++];
}
c += a[i];
}
c += b.substr(j);
// cout << a << " + " << b << " == " << c << endl;
return c;
};
while(sz(q) > 1) {
T a = q.top(); q.pop();
T b = q.top(); q.pop();
T c = mp(a.f + b.f, merge(a.s, b.s));
q.push(c);
}
return q.top().s;
}
// g++-13 -std=c++17 -O2 grader.cpp A.cpp -o A
