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
q = int(input())
for i in range(q):
    n, m = map(int, input().split())
    last_digit = m%10
    cycles = n // m
    value_cycle = {2: (5, 20), 3: (10, 45), 4: (5, 20), 5: (2, 5), 6: (5, 20), 7: (10, 45),
                   8: (5, 20), 9: (10, 45), 0: (1, 0), 1:(10, 45)}
    val = value_cycle[last_digit]
    quo = cycles // val[0]
    rest = cycles % val[0]
    r = 0
    su = 0
    for j in range(rest):
        su += m
        r += su%10
    print(quo * val[1] + r)
    
    
