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
d = {}
d[1] = [1,2,3,4,5,6,7,8,9,0]
d[2]= [2,4,6,8,0]
d[3] = [3,6,9,2,5,8,1,4,7,0]
d[4] = [4,8,2,6,0]
d[5] = [5,0]
d[6]= [6,2,8,4,0]
d[7]= [7,4,1,8,5,2,9,6,3,0]
d[8] = [8,6,4,2,0]
d[9] = [9,8,7,6,5,4,3,2,1,0]
d[0] = [0]
b = [0, 45, 20, 45, 20, 5, 20, 45, 20, 45]
c = [1, 10, 5, 10, 5, 2, 5, 10, 5, 10]
a = int(input())
for i in range(a):
    n,m = map(int, input().split())
    mm = m%10
    nn = n//m
    s = (nn//c[mm])*b[mm]
    for i in range(nn%c[mm]):
        s+=d[mm][i]
    print(s)
    
