// lhzawa(https://www.cnblogs.com/lhzawa/)
// Problem: Best Carry Player 2
// Contest: Virtual Judge - QOJ
// URL: https://vjudge.net/problem/QOJ-6300
// Memory Limit: 1024 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include<bits/stdc++.h>
using namespace std;
const int N = 38;
#define ll __int128
__int128 p10[N + 5];
char s[N];
int val[N];
void write(ll a) {
	if (a > 9) {
		write(a / 10);
	}
	putchar(a % 10 + '0');
	return ;
}
__int128 f[N][N][2];
bool g[N][N][2];
void solve() {
	int l;
	scanf("%s%d", s, &l);
	int n = strlen(s);
	reverse(s, s + n);
	memset(val, 0, sizeof(val));
	for (int i = 0; i < n; i++) {
		val[i] = s[i] - '0';
	}
	if (! l) {
		for (int i = 0; i < n; i++) {
			if (val[i] != 9) {
				write(p10[i]), putchar('\n');
				return ;	
			}
		}
		write(p10[n]), putchar('\n');
		return ;
	}
	memset(g, 0, sizeof(g));
	for (int i = 0; i < N; i++) {
		for (int j = 0; j <= l; j++) {
			for (int k = 0; k <= 1; k++) {
				f[i][j][k] = p10[N];
			}
		}
	}
	f[0][0][0] = 0, g[0][0][0] = 1;
	if (val[0]) {
		f[0][1][1] = (ll)(10 - val[0]), g[0][1][1] = 1;
	}
	__int128 ans = p10[N];
	for (int i = 0; i < N - 1; i++) {
		for (int j = 0; j <= l; j++) {
			for (int k = 0; k <= 1; k++) {
				if (! g[i][j][k]) {
					continue;
				}
				// printf("%d %d %d -> ", i, j, k);
				// write(f[i][j][k]), putchar('\n');
				if (j == l) {
					if (val[i + 1] + k != 10) {
						ans = min(ans, f[i][j][k]);
					}
					continue; 
				}
				int v = val[i + 1] + k;
				if (v == 10) {
					// printf("%d %d %d -> %d %d %d\n", i, j, k, i + 1, j + 1, 1);
					f[i + 1][j + 1][1] = min(f[i + 1][j + 1][1], f[i][j][k]), g[i + 1][j + 1][1] = 1;
				}
				else if (v == 0) {
					// printf("%d %d %d -> %d %d %d\n", i, j, k, i + 1, j, 0);
					f[i + 1][j][0] = min(f[i + 1][j][0], f[i][j][k]), g[i + 1][j][0] = 1;
				}
				else {
					// printf("%d %d %d -> %d %d %d\n", i, j, k, i + 1, j, 0);
					// printf("%d %d %d -> %d %d %d\n", i, j, k, i + 1, j + 1, 1);
					f[i + 1][j][0] = min(f[i + 1][j][0], f[i][j][k]), g[i + 1][j][0] = 1;
					f[i + 1][j + 1][1] = min(f[i + 1][j + 1][1], p10[i + 1] * (ll)(10 - v) + f[i][j][k]), g[i + 1][j + 1][1] = 1;
				}
			}
		}
	}
	write(ans), putchar('\n');
	return ;
}
int main() {
	p10[0] = 1;
	for (int i = 1; i <= N; i++) {
		p10[i] = p10[i - 1] * (ll)(10);
	}
	int _;
	scanf("%d", &_);
	for (; _; _--) {
		solve();
	}
	return 0;
}