#include <iostream>
#include <algorithm>
using namespace std;

string add(string a, int b) {
	int i = 0;
	reverse(a.begin(), a.end());
	while (b || i < a.size()) {
		if (i >= a.size()) {
			a.push_back('0');
		}
		int d = a[i] - '0';
		int sum = d + (b % 10);
		b += ((sum / 10) * 10);
		b /= 10;
		a[i] = '0' + (sum % 10);
		i++;
	}
	reverse(a.begin(), a.end());
	return a;
}

int mod(string a, int b) {
	int i = 0;
	int sum = 0;
	while (i < a.size()) {
		int d = a[i] - '0';
		sum *= 10;
		sum += d;
		sum %= b;
		i++;
	}
	return sum;
}
int main() {
	int t;
	cin >> t;
	string x;
	int y;
	while (t--) {
		cin >> x >> y;
		int m = mod(x, y);
		if (m % y == 0) {
			cout << x << endl;
		}
		else {
			m = (y - (m % y));
			x = add(x, m);
			cout << x << endl;
		}
	}
}