#include <iostream>
using namespace std;
#define ll long long int

int main() {
	ll t, first, second;
	cin >> t;
	while (t--) {
		cin >> first >> second;
		ll k = first;
		if (k < second)
			cout << second << endl;
		else if(k >= second) {
			while (k % second != 0) {
				k++;
			}
			cout << k << endl;
		}
	}
	
}