不会还有人贴吧？

#include<iostream>
using namespace std;
int main(){
    \\freopen("a+b.in","r",stdin);
    \\freopen("a+b.out","w",stdout);
    
    int a,b;
    cin >> a >> b;
    cout << a + b;

    \\fclose(stdin);
    \\fclose(stdout);
    return 0;
}