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
def make_ring(base):
    base %= 10
    ring = [base]
    while True:
        nxt = (ring[-1] + base) % 10
        #print(ring[-1], base, nxt)
        if nxt in ring:
            break
        else:
            ring.append(nxt)
    return ring

q = int(input())
for _ in range(q):
    n, m = map(int, input().split())
    k = n // m              #вычисляет количество элементов удовлетворяющих условию делимости на m
    ring = make_ring(m)     #создает кольцо вычетов по основанию m
    ln = len(ring)
    sm = sum(ring)

    main = k // ln          # сколько пройдет оборотов по кольцу вычетов
    rest = k % ln           # сколько останется посчитать

    result = main * sm + sum(ring[0:rest])
    print(result)

