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
t = int(input())
x1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0]
x2 = [2, 4, 6, 8, 0]
x3 = [3, 6, 9, 2, 5, 8, 1, 4, 7, 0]
x4 = [4, 8, 2, 6, 0]
x5 = [5, 0]
x6 = [6, 2, 8, 4, 0]
x7 = [7, 4, 1, 8, 5, 2, 9, 6, 3, 0]
x8 = [8, 6, 4, 2, 0]
x9 = [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
for i in range(t):
    n, m = map(int, input().split())
    no = n//m
    l = m % 10
    if(l == 1):
        p = no//10
        total = (sum(x1)*p) + sum(x1[:no-(p*10)])
        print(total)
    elif(l == 2):
        p = no//5
        total = (sum(x2)*p) + sum(x2[:no-(p*5)])
        print(total)
    elif(l == 3):
        p = no//10
        total = (sum(x3)*p) + sum(x3[:no-(p*10)])
        print(total)
    elif(l == 4):
        p = no//5
        total = (sum(x4)*p) + sum(x4[:no-(p*5)])
        print(total)
    elif(l == 5):
        p = no//2
        total = (sum(x5)*p) + sum(x5[:no-(p*2)])
        print(total)
    elif(l == 6):
        p = no//5
        total = (sum(x6)*p) + sum(x6[:no-(p*5)])
        print(total)
    elif(l == 7):
        p = no//10
        total = (sum(x7)*p) + sum(x7[:no-(p*10)])
        print(total)
    elif(l == 8):
        p = no//5
        total = (sum(x8)*p) + sum(x8[:no-(p*5)])
        print(total)
    elif(l == 9):
        p = no//10
        total = (sum(x9)*p) + sum(x9[:no-(p*10)])
        print(total)
    else:
        print(0)