#include <functional> #include <algorithm> #include <iostream> #include <iomanip> #include <cstring> #include <string> #include <vector> #include <random> #include <bitset> #include <queue> #include <cmath> #include <stack> #include <set> #include <map> typedef long long ll; using namespace std; const ll MOD = 1000000007LL; int main() { cin.sync_with_stdio(false); cin.tie(0); cout.tie(0); double n, k; cin >> n >> k; cout << n / 2 << "\n"; return 0; }