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
"""
useful stuff 
x= list(map(int,input().split()))
x =[int (e) for e in input().split()]

swap x,y=y,x
substring a[x:y] mean x to y-1

print list
print(*list)
print(' '.join(map(str,listname)))

start from 1 to n
for i in range(1,n+1)

Don't froget dumb stuff like:
if: 
for:
while: 
and tab
def doesn't require data type
"""
q=int(input())
p =[0,10,5,10,5,2,5,10,5,10]
for qq in range(q):
    n,m= [int (e) for e in input().split()]
    x=m%10
    if(x==0):
        print(0)
        continue
    s=0
    cur=x
    for i in range (p[x]):
        s+=cur
        cur+=x
        cur%=10
    res = n//m
    ans=0
    ans+= s*(res//p[x])
    rr= res %p[x]
    cur=x
    for i in range(rr):
        ans+=cur
        cur+=x
        cur%=10
    print(ans)

