#include <bits/stdc++.h>
using namespace std;
#define lf "\n"
#define ff endl
#define _ << ' ' <<
#define all(x) begin(x),end(x)
#define rall(x) rbegin(x),rend(x)
#define infos(str) do { fprintf(stderr, str"\n"); } while(0)
#define infor(str, ...) do { fprintf(stderr, str, __VA_ARGS__); } while(0)
#define infof(str, ...) do { fprintf(stderr, str"\n", __VA_ARGS__); } while(0)
#ifndef DEBUG
#undef infos
#undef infor
#undef infof
#define infos(str)
#define infor(str, ...)
#define infof(str, ...)
#endif
using ll = long long;
constexpr int LOG = 20;
constexpr int MOD = 1e9+7;
constexpr int MAXN = 1e5+7;
std::pair<std::vector<int>, long long> transaction(long long M);
void buy_souvenirs(int N, long long P0) {
if(N == 2) return (void)(transaction(P0 - 1));
assert(N == 3);
auto [q, x] = transaction(P0 - 1);
ll pay = P0 - 1 - x;
if(q.size() == 1) {
transaction(pay - 1);
transaction(pay - 1);
return;
}
transaction((pay - 1) / 2);
}
