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
#import bisect
#i = bisect.bisect_left(a, k)
#a=[]
#from sys import stdin
#input=stdin.readline
        
for _ in range (int(input())):
    #n=int(input()) 
    ans=0
    n,m=map(int, input().split())
    #a=list(map(int, input().split()))
    a=[]
    if m>n:
        print('0')
        continue
    for i in range(10):
        a.append((m*(i+1))%10)
    s=sum(a)
    
    ans+=((n//(m*10))*s)
    k=n%(10*m)
    p=k//m
    for i in range(p):
        ans+=a[i]
    print(ans)
    #YOUR CODE HERE
