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 process(n, m):
    a=n//m
    b=a%10
    c=a//10
    cycle=0
    for i in range(1, 11):
        cycle=cycle+(m*i)%10
    sum2=0
    for i in range(1,b+1):
        sum2=sum2+(m*i)%10
    return cycle*c+sum2
    
# def naive(n, m):
#     a=n//m
#     F=[]
#     for i in range(1, a+1):
#         F.append((m*i)%10)
#     return sum(F) 
    
 
t= int(input())
for i in range(t):
    n, m=[int(x) for x in input().split()]
    print(process(n,m))
# n, m=[int(x) for x in input().split()]
# print(process(n,m))
