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())
#import fractions
import math
def lcm_base(x, y):
  return (x * y) // math.gcd(x, y)

for _ in range(q):
    n, m = map(int, input().split())
    q, r = divmod(n, m)
    l =  lcm_base(m, 10)
    s = l//m
    L = [0]*(s+1)
    for i in range(s):
        L[i+1] = L[i]+(m*(i+1))%10
    #print(L)
    q2, r2 = divmod(q, s)
    ans = L[-1]*q2+L[r2]
    print(ans)
