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
from sys import stdin
RI = lambda : map(int,stdin.readline().split())

f = [[0],
     [0,1,3,6,10,15,21,28,36,45],
     [0,2,6,12,20],
     [0,3,9,18,20,25,33,34,38,45],
     [0,4,12,14,20],
     [0,5],
     [0,6,8,16,20],
     [0,7,11,12,20,25,27,36,42,45],
     [0,8,14,18,20],
     [0,9,17,24,30,35,39,42,44,45] ]

for _ in xrange(input()):
    n,m = RI()
    y = n/m
    l = m%10

    val = (y/len(f[l]))*f[l][-1]
    val += f[l][y%len(f[l])]

    print val
