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 sys
#sys.stdin=open("input.txt")
T=int(input())
for t in range (0,T):
    L=list (map(int,input().split()))
    N=(L[0])
    M=(L[1])
    somma=0
    multipli=M*10
    gruppi=N//multipli
    resto=N%multipli
    tgruppi=0
    tresto=0
    for n in range (M,multipli,M):
        pagine=str(n)
        p=len(pagine)
        cifra=int(pagine[p-1])
        tgruppi=tgruppi+cifra
    pmultipli=tgruppi*gruppi
    for m in range (M,resto+1,M):
        pagine=str(m)
        p=len(pagine)
        cifra=int(pagine [p-1])
        tresto=tresto+cifra
    presto=tresto
    somma=somma+pmultipli+presto    
    print (somma) 
