#include <bits/stdc++.h>
using namespace std;

int T, m, pw[9];
string n;

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	pw[0] = 1;
	for (int i = 1; i <= 8; i++) {
		pw[i] = pw[i - 1] * 10;
	}
	cin >> T;
	while (T--) {
		cin >> n >> m;
		int valn = 0;
		for (char c : n) {
			valn = (10ll * valn + c - '0') % m;
		}
		int cnt = m - valn - 1;
		int now = (int)n.size() - 1;
		while (now >= 0 && n[now] == '9') {
			n[now] = '0';
			now--;
		}
		if (now == -1) {
			n = '1' + n;
		} else {
			n[now]++;
		}
		reverse(n.begin(), n.end());
		string strm = "";
		int valm = m;
		while (valm) {
			strm += valm % 10 + '0';
			valm /= 10;
		}
		if (n.find(strm)) {
			reverse(n.begin(), n.end());
			cout << n << '\n';
			continue;
		}
		long long sum = 1;
		for (int i = 0; i < n.size(); i++) {
			long long v = 0;
			for (int j = i; j < min(i + strm.size(), n.size()); j++) {
				v += (n[j] - '0') * pw[j - i];
			}
			long long dis = m - v;
			if (dis > 0) {
				if (i >= 9) {
					if (dis == 1 && sum < cnt) {
						cnt = sum;
					} 
				} else if ((dis - 1) * pw[i] + sum < cnt) {
					cnt = (dis - 1) * pw[i] + sum;
				}
			}
			if (n[i] != '9') {
				if (i >= 9) {
					break;
				} else {
					sum += ('9' - n[i]) * pw[i];
				}
			}
		}
		for (int i = 0; i < n.size(); i++) {
			int c = n[i] - '0';
			n[i] = (c + cnt) % 10 + '0';
			cnt = (c + cnt) / 10;
		}
		while (cnt) {
			n += cnt % 10 + '0';
			cnt /= 10;
		}
		reverse(n.begin(), n.end());
		cout << n << '\n';
	}

	return 0;
}