def myint(x : str):
    if len(x) == 0:
        return int(0)
    return int(x)

T = int(input())
for _ in range(T):
    n, m = input().split()
    N = int(n)
    M = int(m)
    N += 1
    n = str(N)
    if n.find(m) != -1:
        print(N)
        continue
    Ans = (N + M - 1) // M * M
    # if len(n) < len(m):
    #     B = M
    # else:
    #     if myint(n[-len(m):]) <= M:
    #         B = myint(n[:-len(m)] + m)
    #     else:
    #         B = A
    
    # if(len(n) + 1 < len(m)):
    #     C = M * 10
    # else:
    #     if myint(n[(-len(m) - 1):]) <= M * 10:
    #         C = myint(n[:(-len(m) - 1)] + m + '0')
    #     elif myint(n[(-len(m) - 1):]) <= M * 10 + 9:
    #         C = myint(n[:(-len(m) - 1)] + m + n[-1:])
    #     else:
    #         C = myint(str(myint(n[:(-len(m) - 1)]) + 1) + m + '0')
    
    orgN = N
    nn = n[-25:]
    ri = M
    now = int(0)
    for i in range(11):
        tmp = myint(nn[-(len(m)+i):])
        if tmp <= M * 10**i:
            ri = min(ri, M * 10**i - tmp)
        
        if now < ri:
            if(len(n) >= i + 1):
                ch = int(n[-i-1])
            else:
                ch = 0
            now += (10 - ch) * 10**i
            if now < ri:
                N += (10 - ch) * 10**i
                n = str(N)
                if n.find(m) != -1:
                    ri = min(ri, now)

    # print(ri)
    Ans = min(Ans, orgN + ri)    
    print(Ans)

answer.code:20:13: error: missing binary operator before token "("
   20 |     # if len(n) < len(m):
      |             ^
answer.code:22:11: warning: extra tokens at end of #else directive [-Wendif-labels]
   22 |     # else:
      |           ^
answer.code:23:19: error: missing binary operator before token "("
   23 |     #     if myint(n[-len(m):]) <= M:
      |                   ^
answer.code:25:15: warning: extra tokens at end of #else directive [-Wendif-labels]
   25 |     #     else:
      |               ^
answer.code:26:15: error: invalid preprocessing directive #B
   26 |     #         B = A
      |               ^
answer.code:28:13: error: missing binary operator before token "("
   28 |     # if(len(n) + 1 < len(m)):
      |             ^
answer.code:30:11: warning: extra tokens at end of #else directive [-Wendif-labels]
   30 |     # else:
      |           ^
answer.code:31:19: error: missing binary operator before token "("
   31 |     #     if myint(n[(-len(m) - 1):]) <= M * 10:
      |                   ^
answer.code:33:21: error: missing binary operator before token "("
   33 |     #     elif myint(n[(-len(m) - 1):]) <= M * 10 + 9:
      |                     ^
answer.code:35:15: warning: extra tokens at end of #else directive [-Wendif-labels]
   35 |     #     else:
      |               ^
answer.code:36:15: error: invalid preprocessing directive #C
   36 |     #         C = myint(str(myint(n[:(-len(m) - 1)]) + 1) + m + '0')
      |               ^
answer.code:59:7: error: invalid preprocessing directive #print
   59 |     # print(ri)
      |       ^~~~~
answer.code:31: error: unterminated #else
   31 |     #     if myint(n[(-len(m) - 1):]) <= M * 10:
      | 
answer.code:28: error: unterminated #else
   28 |     # if(len(n) + 1 < len(m)):
      | 
answer.code:23: error: unterminated #else
   23 |     #     if myint(n[-len(m):]) <= M:
      | 
answer.code:20: error: unterminated #else
   20 |     # if len(n) < len(m):
      | 
answer.code:4:1: error: ‘def’ does not name a type
    4 | def myint(x : str):
      | ^~~