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
q = int(input())
for i in range(q):
    n,m = input().split()
    if int(n)<int(m) or int(m[len(m)-1])==0:
        print(0)
        continue
    arr = [0,45,20,45,20,5,20,45,20,45]
    arr1 = [0,10,5,10,5,2,5,10,5,10]
    ans = 0
    y = int(m[len(m)-1])
    nomul = int(n)//int(m)
    rem = nomul%10
    ans = ans + ((nomul-rem)//arr1[y])*arr[y]
    #sum of remno of y multiples
    x = y
   # print(ans)
   # print(rem)
    z = y
    while rem>0:
        ans+=z
        z+=y
        z = z%10
        rem-=1
    print(ans)









    

     