#include <stdio.h>
#include <string.h>

#include <vector>
#include <algorithm>

#define eb emplace_back

using namespace std;

typedef long long LL;
typedef __int128 LLL;
constexpr int N = 100005;

LLL wt[40];

char a[64];
int K;
LLL res;

void dfs(int dep, int req, LLL cur) {
	if (cur >= res || dep >= 37) {
		return;
	}
	if (req == 0) {
		res = cur;
		return;
	}
	if (cur + (10 - a[dep]) * wt[dep] >= res) {
		return;
	}
	if (a[dep]) {
		int i = dep + 1;
		while (a[i] == 9) {
			++i;
		}
		if (i - dep <= req) {
			a[i] += 1;
			dfs(i, req - (i - dep), cur + (10 - a[dep]) * wt[dep]);
			a[i] -= 1;
		}
	}
	dfs(dep + 1, req, cur);
}

void write(LLL res) {
	if (res > 9) {
		write(res / 10);
	}
	printf("%d", (int)(res % 10));
}

LLL solve() {
	if (K == 0) {
		int i = 0;
		while (a[i] == 9) {
			i += 1;
		}
		return wt[i];
	}
	res = wt[37];
	dfs(0, K, 0);
	return res;
}

int main() {
	*wt = 1ll;
	for (int i = 1; i < 38; ++i) {
		wt[i] = wt[i - 1] * 10;
	}
	int task;
	for (scanf("%d", &task); task--; ) {
		memset(a, 0, sizeof a);
		scanf("%s%d", a, &K);
		int len = strlen(a);
		for (int i = 0; i < len; ++i) {
			a[i] ^= 48;
		}
		reverse(a, a + len);
		write(solve()), puts("");
	}
	return 0;
}