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 ip(): return [int(i) for i in stdin.readline().split()]
def sp(): return [str(i) for i in stdin.readline().split()]
def pp(A): 
    for i in A: print(i)


def solve():
    n,m = ip()
    A = []
    rs = 0
    ts = 0
    for _ in range(10):
        rs += m
        ts += rs % 10
        A.append(rs % 10)
    g = n//m
    d,r = g//10, g%10
    ans = d*ts
    # print(f'{A=} | {rs=} | {ts=} | {g=}')
    for i in range(r):
        ans += A[i]
    return ans


t = int(input())
for _ in range(t):
    print(solve())