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
q = int(input())
for i in range(q):
    n, m = map(int, input().split())
    per = [m % 10]
    per_sum = m % 10
    k = 2 * m
    kol1 = 1
    while m % 10 != k % 10:
        per.append(k % 10)
        kol1 += 1
        per_sum += k % 10
        k += m
    kol = n // m
    sum1 = 0
    sum1 += kol // kol1 * per_sum
    kol -= kol // kol1 * kol1
    for i in range(kol):
        sum1 += per[i]
    print(sum1)
