HJ22 汽水瓶

#include <iostream>
using namespace std;

int main() {
    int a;
    while (cin >> a) {
        if(a == 0){
            break;
        }

        int count = 0;
        while (a >= 2) {
            a -= 2;
            count++;
        }
        cout << count << endl;
    }
}