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
input = sys.stdin.readline

def solve():
    n, m = map(int, input().split())
    if m % 10 == 0:
        print(0)
        return 0
    cycle = (0, (10, 45), (5, 20), (10, 45), (5, 20), (2, 5), (5, 20), (10, 45), (5, 20), (10, 45))
    M = m % 10
    sum = n // m // cycle[M][0] * cycle[M][1]
    n = n // m % cycle[M][0]
    for i in range(n):
        sum += M * (i + 1) % 10
    M = m
    print(sum)
t = int(input())
for _ in range(t):
    solve()

