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, heapq

num = {1 : [1,2,3,4,5,6,7,8,9,0], 2 : [2,4,6,8,0], 3 : [3,6,9,2,5,8,1,4,7,0], 4 : [4,8,2,6,0],
       5 : [5,0], 6 : [6,2,8,4,0], 7 : [7,4,1,8,5,2,9,6,3,0], 8 : [8,6,4,2,0], 9 : [9,8,7,6,5,4,3,2,1,0], 0 : [0]}

tc = int(sys.stdin.readline())
for _ in range(tc):
    n, m = map(int, sys.stdin.readline().split())
    size = n // m
    last = int(str(m)[-1])
    q = size // len(num[last])
    mid = q * sum(num[last])
    size %= len(num[last])
    left = 0
    for i in range(size):
        left += num[last][i]
    print(mid + left)