[백준] 5565번 : 영수증 - C++

https://www.acmicpc.net/problem/5565

#include <iostream>

using namespace std;

int main() {
    int sum;
    cin>>sum;
    for(int i=0;i<9;i++){
        int a;
        cin>>a;
        sum-=a;
    }
    cout<<sum;
}