Polycarp is reading a book consisting of n pages numbered from 1 to n. Every time he finishes the page with the number divisible by m, he writes down the last digit of this page number. For example, if n=15 and m=5, pages divisible by m are 5, 10, 15. Their last digits are 5, 0, 5 correspondingly, their sum is 10.

Your task is to calculate the sum of all digits Polycarp has written down.

You have to answer q independent queries.

Input

The first line of the input contains one integer q (1 ≤ q ≤ 1000) — the number of queries.

The following q lines contain queries, one per line. Each query is given as two integers n and m (1 ≤ n, m ≤ 10^{16}) — the number of pages in the book and required divisor, respectively.

Output

For each query print the answer for it — the sum of digits written down by Polycarp.

Example

Input


7
1 1
10 1
100 3
1024 14
998244353 1337
123 144
1234312817382646 13


Output


1
45
153
294
3359835
0
427262129093995
##import sys
##sys.stdin = open("input.txt")
Q = int(input()) 
for q in range(Q):
    N,M = map(int,input().split())
    S = 0
    C = []
    s = 0
##    for k in range(N):
##        if k % M ==0:
##            print (k, end= " ")
##            s = s +int(str(k)[-1])
##    print()
    for k in range(1,11):
        if int(str(k*M)[-1]) not in C:
            C.append(int(str(k*M)[-1]))
            S = S + C[-1] 
    s = 0
    D = N //M
    A = D // len(C)
    s = S * A
    A = D % len(C)
    for a in range(A):
        s = s + C[a]
        
    print (s)
