#include <iostream>
using namespace std;


int main() {
	int x, y, counter=0 , n,k;
	int a[100000], b[100000];
	cin >> n;
	

	for (int i = 0; i < n; i++) {
		cin >> x >> y;

		for (int i = 0; i < 10000; i++) {

			a[i] = i * y;
			if ((a[i] > x) && (a[i] % y == 0)) {
				k = a[i];
				b[counter] = k;
				counter++;
				
				break;
				
			}
		}
		
		
	}
	for (int j = 0; j < n; j++) {
		cout << b[j] << endl;
	}
	

	return 0;
}