import sys
import math

def solve(x, m):
    dp = [[[float('inf')] * 2 for _ in range(20)] for _ in range(40)]
    a = [0] * 40
    cnt = 0
    while x:
        cnt += 1
        a[cnt] = x % 10
        x //= 10
    
    num = [1] * 40
    for i in range(1, 37):
        num[i] = num[i - 1] * 10

    dp[0][0][0] = 0

    if m == 0:
        for i in range(1, cnt + 2):
            if a[i] != 9:
                print(num[i - 1])
                return

    for i in range(1, 37):
        for k in range(0, m + 1):
            if a[i] + 1 < 10:
                dp[i][k][0] = min(dp[i - 1][k][1], dp[i - 1][k][0])
            else:
                dp[i][k][0] = dp[i - 1][k][0]

            if k != 0:
                if a[i] != 0:
                    dp[i][k][1] = min((10 - a[i] - 1) * num[i - 1] + dp[i - 1][k - 1][1], (10 - a[i]) * num[i - 1] + dp[i - 1][k - 1][0])
                else:
                    dp[i][k][1] = (10 - a[i] - 1) * num[i - 1] + dp[i - 1][k - 1][1]

    ans = float('inf')
    for i in range(cnt, 37):
        ans = min(ans, min(dp[i][m][1], dp[i][m][0]))

    print(ans)
    return


def main():
    t = int(input())
    for _ in range(t):
        (x, m) = map(int, input().split())
        solve(x, m)


if __name__ == "__main__":
    main()