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
query=int(input())
for i in range(query):
    x=input()
    x=x.split(" ")
    n=int(x[0])
    m=int(x[1])
    if n>=(10*m):
        x=10*m
        digits=0
        result=0
        newm=m
        while newm < x:
            digits+=(newm%10)
            newm+=m
        result+=digits*((n//m)//10)
        #start from ((n//m)//10) to n
        x=(n-((n//m)//10)*10*m)
        digits=0
        newm=m
        while newm <= x:
            digits+=(newm%10)
            newm+=m
        #if(n%m==0)
        result+=digits
        print(result)
    elif n<m:
        print(0)
    elif n==m:
        print(m%10)
    else:
        result=0
        x=m*(n//m)#mod?
        newm=m
        while newm <= x:
            result+=(newm%10)
            newm+=m
        print(result)
