#include <bits/stdc++.h> std::pair<std::vector<int>, long long> transaction(long long M); void buy_souvenirs(int N, long long P0) { std::vector<int32_t> bought(N, 0); for(int32_t type = 1; type < N; type++) { while(bought[type] < type) { for(int64_t M = 1; M < P0; M++) { auto transactions = transaction(M); auto& L = transactions.first; if(static_cast<int32_t>(L.size()) == 1 && L[0] == type) { bought[type]++; break; } } } } }