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 ultAlg(n):
    strN = str(n)
    return int(strN[-1])

q = int(input())

for i in range(q):
    input1 = input().split()
    n = int(input1[0])
    m = int(input1[1])
    mUltimo = int(input1[1][-1])
    somaTotal = 0
    divisao = n // (m * 10)

    if (mUltimo == 0):
        somaTotal = 0
    elif (mUltimo == 5):
        somaTotal = 25 * divisao
    elif (mUltimo % 2 == 0):
        somaTotal = 40 * divisao
    else:
        somaTotal = 45 * divisao

    nDivisao = divisao * m * 10

    nDivisao += m

    while (n >= nDivisao):
        somaTotal += ultAlg(nDivisao)
        nDivisao += m

    print(somaTotal)
	 					  		 			 	 	    				  	