// Ignut
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int use_machine(vector<int> x);
int count_mushrooms(int n) {
int res = 1;
int firstA = 0, secondA = -1;
vector<int> vec;
for (int i = 1; i < n; i ++) vec.push_back(i);
while (vec.size() > 1) {
int u = vec.back(); vec.pop_back();
int v = vec.back(); vec.pop_back();
if (secondA != -1) {
int val = use_machine({firstA, u, secondA, v});
if (val == 0) res += 2;
else if (val == 1) res ++;
else if (val == 2) res ++;
continue;
}
int val = use_machine({u, firstA, v});
if (val == 0) {
secondA = u;
res += 2;
}
else if (val == 1) {
res ++;
val = use_machine({firstA, u});
if (val == 0)
secondA = u;
else
secondA = v;
}
}
if (!vec.empty()) {
int val = use_machine({firstA, vec.back()});
if (val == 0) res ++;
}
return res;
}
