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 sys
#sys.stdin = open("input.txt")

T= int(input())
for x in range (T):
    tab = []
    somma = 0
    n,m = map(int,input().split())
    somma = 0

    for y in range (1,11):
        c = m*y
        c = str(c)
        if int(c[-1]) not in tab:
            if int(c) < 10:
                c = int(c)
                somma = somma+c
                tab.append(c)
            else:
                c = int(c[-1])
                somma = somma+c
                tab.append(c)
        else:
            break
    
    R = (n // m)
    r = R//len(tab)
    q = R % len(tab)
    risultato = somma*r
    for y in range (q):
        risultato += tab[y]
    print (risultato)

    
        
