题解 | #汽水瓶#

#include <iostream>
using namespace std;

int main() {
    int n;
    int cn=0;
    while(cin >> n && n != 0){
        if(n < 2){
            cout << cn << endl;
        }else if(n == 2){
            cn++;
            cout << cn << endl;
        }else{
            while(n >= 3){
                n = n - 3;
                cn ++;
                n = n + 1;
            }
            if(n == 2){
                cn++;
            }
        }
        cout << cn << endl;
        cn =0;
    }
    
    return 0;
}
// 64 位输出请用 printf("%lld")