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
from sys import stdin, stdout

q = int(stdin.readline())

for xablau in range(q):
    n,m = map(int, stdin.readline().rstrip().split())
    result = 0
    dicionario = []
    soma = 0
    if n >= m:
        for num in range(11):
            strg = str(num*m)
            dicionario.append(int(strg[len(strg)-1]))
            soma = soma + int(strg[len(strg)-1])
    
        string = str(n//m)
        el = 0
        for d in range(len(string)):

            inv = len(string)-d-1
            if inv+1  == len(string):
                sumdicio = 0
                for kk in range(int(string[inv])+1):
                    sumdicio += dicionario[kk]
                result = result + sumdicio
            if inv+1 <= len(string):
                result = result + ((10 **el)/10) * soma * int(string[inv])

            #print("inv", inv, "result", result)

            el += 1
    print result
