#include <iostream>
using namespace std;
int a[100000] = { 0 };
int main()
{
    int t;
    int idx = 0;
    cin >> t;
    for (int i = 0;i < t;i++) {
        int x, y;
        cin >> x >> y;
        int k = x;
        for (int i = 0;i < 1e9;i++) {
            if (k % y == 0) {
                a[idx] = k;
                idx++;
                break;
            }
            k++;
        }
    }
    for (int i = 0;i < idx;i++) {
        cout << a[i] << endl;
    }
}