#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
int count_mushrooms(int n) {
int ans = 0;
vector<int> a[2], v(n - 1);
iota(v.begin(), v.end(), 1);
a[0] = {0};
for (; (int)a[0].size() < 2 && (int)a[1].size() < 2 && v.size();) {
a[use_machine({0, v.back()})].push_back(v.back());
v.pop_back();
}
int S = 120;
int ind = a[1].size() > 1;
for (; (int)a[0].size() <= S && (int)a[1].size() <= S && v.size() > 1;) {
int res = use_machine({a[ind][0], v[v.size() - 2], a[ind][1], v.back()});
a[(res < 2) ^ (!ind)].push_back(v[v.size() - 2]);
a[(res % 2) ^ (ind)].push_back(v.back());
v.pop_back();
v.pop_back();
}
while (v.size()) {
int use = min((int)v.size(), S);
int ind = (int)a[1].size() > use;
vector<int> ask;
for (int i = 0; i < 2 * use + 1; ++i) {
if (i & 1) {
ask.push_back(v.back());
v.pop_back();
}
else {
ask.push_back(a[ind][i / 2]);
}
}
if (ind) {
ans += use_machine(ask) / 2;
}
else {
ans += use - use_machine(ask) / 2;
}
}
return ans + a[0].size();
}
