题解 | #汽水瓶#

#include <iostream>
#include <vector>

using namespace std;

void process(int num, int& ans){
    if(num < 2) ans = 0;
    
    while(num >= 2){       
        ans += 1;
        num -= 3;
        num += 1;
    }  
}

int main(){
    int num = 0;
    vector<int> res;
    while(cin>>num && num != 0){
        int ans = 0;
        process(num, ans);
        res.push_back(ans);
    }
    
    for(int i = 0; i < res.size(); i++){
        cout<<res[i]<<endl;
    }
    
    return 0;
}