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
n=0
m=0
t=0
t=int(input())
while t>0:
    n,m=input().split(" ")
    n=int(n)
    m=int(m)
    sum=0
    sumt=0
    k=0
    for i in range(1,11):
        k=m*i
        sumt+=(k%10)
    #print(sumt)
    k=0
    a=int(n/(m*10))
    sum=sumt*a
    a=a*(m*10)

    while a<n :
        a += m
        if(a>n):
            break;
        sum += (a % 10)


    print(sum)
    t-=1



