#include <bits/stdc++.h>
using namespace std;
#define ll long long
void ckmin(ll &x, ll y) {x = min(x, y);}
const int N = 19;
int k,bit[N];
char str[N+1];
ll shi[N],dp[N][N][2];
void solve(int id) {
	scanf("%s%d", str + 1, &k);
	memset(bit, 0, sizeof bit);
	int n = strlen(str + 1);
	int m = n;
	int zero = 0;
	while (m >= 1 && str[m] == '0') m --, zero ++;
//	memset(dp, 0x3f, sizeof dp); // ?? 太小 ?? 
	for (int i = 0; i < N; i ++)
		for (int j = 0; j < N; j ++)
			dp[i][j][0] = dp[i][j][1] = 1e18-1;
	for (int i = 1, j = m; i <= m; i ++, j --)
		bit[i] = str[j] - '0';
	dp[0][0][0] = 0;
	for (int i = 1; i < N; i ++) {
		int a = bit[i];
		for (int j = 0; j <= k; j ++) {
			// 第 i 位 没有进位  i - 1 not
			ckmin(dp[i][j][0],dp[i - 1][j][0]);
			// i - 1 yes
			if (a != 9)ckmin(dp[i][j][0], dp[i - 1][j][1]); 
			if (j) {
				ll need = 10 - a;
				if(a)ckmin(dp[i][j][1], need * shi[i - 1] + dp[i - 1][j - 1][0]);
				// i - 1 yes
				need = 9 - a;
				ckmin(dp[i][j][1], need * shi[i - 1] + dp[i - 1][j - 1][1]);
			}
		}
	}
	ll ans = min({dp[N - 1][k][0],dp[N-1][k][1]});
	if (ans==0) {
		vector<int> ans;
		for (int i = n; i >= 1; i --) {
			if (i == 1 || str[i] != '9') {ans.push_back(1);break;}
			ans.push_back(0);
		}
		reverse(ans.begin(), ans.end());
		for (auto p : ans)
			cout << p;
		puts("");
		return; 
	}
	printf("%lld", (long long)ans);
	for (int i = 1; i <= zero; i ++)
		printf("0");
	puts("");
}
int main() {
	shi[0] = 1;
	for (int i = 1; i < N; i ++)shi[i] = shi[i - 1] * 10;
	int T;
	cin >> T;
	for (int i = 1; i <= T; i ++)solve(i);
}