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
#arr=[[1,2,3,4,5,6,7,8,9,0],[2,4,6,8,0,2,4,6,8,0],[3,6,9,2,5,8,1,4,7,0],[4,8,2,6,0,4,8,2,6,0],[5,0,5,0,5,0,5,0,5,0],[6,2,8,4,0,6,2,8,4,0],[7,4,1,8,5,2,9,6,3,0],[8,6,4,2,0,8,6,4,2,0],[9,8,7,6,5,4,3,2,1,0]]
for _ in range(input()):
    n,m = map(int,raw_input().split())
    num = n/m
    m = m%10
    arr=[0 for i in range(12)]
    for i in range(1,11):
        if(i==1):
            arr[i]=m%10
        else:
            arr[i]=(m*i)%10+arr[i-1]
    su = (num/10)*(arr[10])
    su = su + arr[num%10]
    print su
