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
no_of_test_cases = int(input())

for i in range(no_of_test_cases):
    pages,m = list(map(int,input().split()))
    if pages < m :
        print(0)
        continue
    multiples = pages//m
    mul = multiples
    ans = 0
    count = 1
    visited = []
    while(multiples>0):
        val = (m*count)%10
        if val in visited:
            break
        visited.append(val)
        count+=1
        multiples-=1
    total = mul//len(visited)
    rem = mul-(total*len(visited))
    for i in visited:
        ans += (i*total)
    for i in range(rem):
        ans+= visited[i]
    print(ans)