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 odds(a1, n, m):
    bb = (m % 10) * 10 + 100 * (m // 10)
    aa = (n // bb) * bb
    return sum(a1) * (n // bb) + sum(a1[:int(((n - aa) / bb) * 10)])

def evens(a1, n, m):
    c1 = (m % 10) * 5 + 50 * (m // 10)
    return 20 * (n // c1) + sum(a1[:int(((n % c1) / c1 * 10) / 2)])
    
q = int(input().strip())
for _ in range(q):
    addUp = 0
    store = []
    n, m = map(int, input().strip().split())
    if m % 10 == 0:
        result = 0
    if m % 10 == 1:
        a1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
        result = odds(a1, n, m)
    if m % 10 == 3:
        a1 = [3, 6, 9, 2, 5, 8, 1, 4, 7, 0]
        result = odds(a1, n, m)
    if m % 10 == 7:
        a1 = [7, 4, 1, 8, 5, 2, 9, 6, 3, 0]
        result = odds(a1, n, m)
    if m % 10 == 9:
        a1 = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
        result = odds(a1, n, m)
    if m % 10 == 2:
        a1 = [2, 4, 6, 8, 0]
        result = evens(a1, n, m)
    if m % 10 == 4:
        a1 = [4, 8, 2, 6, 0]
        result = evens(a1, n, m)
    if m % 10 == 6:
        a1 = [6, 2, 8, 4, 0]
        c1 = (m % 10) * 5 + ((m // 10) * 50)
        result = evens(a1, n, m)
    if m % 10 == 8:
        a1 = [8, 6, 4, 2, 0]
        result = evens(a1, n, m)
    if m % 10 == 5:
        if 0 <= n % (m * 2) <= (m // 10) * 10 + 4:
            a = n - n % (m * 2)
            resu = int((a / m) / 2)
        else:
            a = n + ( m - n % (m * 2))
            resu = int(((a - m) / m) / 2) + 1
        result = resu * 5
    
    print(result)
    