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
import math
q = int(input())


for k in range(q):
    n,m = input().split(' ')
    n = int(n)
    m = int(m)
    if(n == m):
        print(int(str(m)[-1]))
    elif(m > n):
        print(0)
    else:
        lastdigit = int(str(m)[-1])
        if lastdigit == 0:
            print(0)
        else:
            paMax = n - n%m
            if lastdigit in [1,3,7,9]:
                a = math.floor((paMax - m)/(10*m))
                lastSum = a*45
                actualNumber = m + a*10*m
            elif lastdigit in [2,4,6,8]:
                a = math.floor((paMax - m)/(5*m))
                lastSum = a*20
                actualNumber = m + a*5*m
            else:
                a = math.floor((paMax - m)/(2*m))
                lastSum = a*5
                actualNumber = m + a*2*m
            while actualNumber <= paMax:
                lastdigit = int(str(actualNumber)[-1])
                lastSum += lastdigit
                actualNumber += m
            print(lastSum)
     		  		 			     						    	