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
def ii(): return int(stdin.readline())
def mi(): return map(int, stdin.readline().split())
def li(): return list(mi())
def si(): return stdin.readline()
def div(x, y):
    s=0
    for i in range(1, y+1):
        s+=(x*i)%10
    return s
for _ in range(ii()):
    n, m=mi()
    x=m%10
    p=n//m
    q=p%10
    p//=10
    b=div(x, 9)
    b*=p
    c=div(x, q)
    print(b+c)