1. Code

#include <iostream>

using namespace std;

int main(void) {
    cin.tie(NULL); // stop flushing the stream
    ios::sync_with_stdio(false); // it asynchronizes the input and output of C and C++

    int n, a, b;
    cin >> n;

    for (int i=0 ; i<n ; i++) {
        cin >> a >> b;
        cout << a+b << "\n";
    }

    return 0;
}

2. Result

        Runtime : 232 ms, Memory usage : 2016 KB
        (Runtime can be different by a system even if it is a same code.)

Check out the my GitHub repo for more info on the code. If you have questions, you can leave a reply on this post.