#include <bits/stdc++.h> using namespace std; pair<vector<int>, long long> transaction(long long M); void buy_souvenirs(int N, long long P0) { vector<int> bought(N, 0); for (int type = 1; type < N; type++) { for (int need = 0; need < type; need++) { bool ok = false; for (long long M = 1; M < P0; M++) { auto res = transaction(M); auto &L = res.first; if ((int)L.size() == 1 && L[0] == type) { ok = true; break; } } if (!ok) return; } } }