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
t = int(input())
ans = []
for _ in range(t):
    arr = list(map(int, input().split()))
    n = arr[0]
    m = arr[1]
    cur_arr = []
    for i in range(m, m * 10 + 1, m):
            cur_arr.append(i % 10)
    residual = n % (10 * m)
    residual /= m
    s = sum(cur_arr)
    s *= (n // (10 * m))
    s += sum(cur_arr[:int(residual)])
    ans.append(s)
for el in ans:
    print(el)