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
table = {1:[1,2,3,4,5,6,7,8,9,0],
    2:[2,4,6,8,0],
    3:[3,6,9,2,5,8,1,4,7,0],
    4:[4,8,2,6,0],
    5:[5,0],
    6:[6,2,8,4,0],
    7:[7,4,1,8,5,2,9,6,3,0],
    8:[8,6,4,2,0],
    9:[9,8,7,6,5,4,3,2,1,0],
    0:[0]}
#print("sad")
#for i in table: print("asdsd",i,len(table[i]))
for test in range(int(input())):
    n,m = map(int,input().split(" "))
    lim = n//m #how many times no is there
    m = int(str(m)[-1])
    s = 0
    full = lim//len(table[m]) #this many times full
    partial = lim%len(table[m])
    if partial!=0:
        for i in range(partial):
            s += table[m][i]
    s += full*sum(table[m])
    print(s)