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
import math
t = int(input())
summa = 0
i = 0
while i < t:
    summa = 0
    m = list(map(int, input().split()))
    if m[1]%10 == 0:
        summa+=0
    elif m[1]%5 == 0:
        summa+=math.ceil(math.floor(m[0]/m[1])/2)*5
    elif m[1]%2 == 0:
        summa+=math.floor(m[0]/m[1]/5)*20
        i2 = 0
        while i2 < math.floor((m[0]-math.floor(m[0]/m[1]/5)*m[1]*5)/m[1]):
            summa += int(str((i2+1)*m[1])[-1])
            i2+=1
    else:
        summa+=math.floor(m[0]/m[1]/10)*45
        i2 = 0
        while i2 < math.floor((m[0]-math.floor(m[0]/m[1]/10)*10*m[1])/m[1]):
            summa += int(str((i2+1)*m[1])[-1])
            i2+=1
    print(summa)
    i+=1
