🐣 문제

링크 : https://www.acmicpc.net/problem/2839

🐥 코드

/*
문제 : 설탕배달 
링크 : https://www.acmicpc.net/problem/2839
*/

#include <iostream>
#include <algorithm>

using namespace std;

int main(){
    int n;
    cin >> n;

    int ans = 0;
    while(true){
        if(n % 5 == 0){
            ans += n / 5;
            break;
        }
        n -= 3;
        ans += 1;

        if(n < 0){
            ans = -1;
            break;
        }
    }

    cout << ans;
    return 0;
}