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 java.util.*;
public class A
{
    public static void main(String args[])
    {
        Scanner sc=new Scanner(System.in);
        int q=sc.nextInt();
        while(q-->0)
        {
            long n=sc.nextLong();
            long m=sc.nextLong();
            String str=Long.toString(m);
            char ch=str.charAt(str.length()-1);
            if(ch=='0')
            System.out.println(0);
            if(m>n&&ch!='0')
            System.out.println(0);
            else
            {
                if(ch=='1')
                {
                    int a[]={1,2,3,4,5,6,7,8,9,0};
                    long temp=45;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='2')
                {
                    int a[]={2,4,6,8,0,2,4,6,8,0};
                    long temp=40;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='3')
                {
                    int a[]={3,6,9,2,5,8,1,4,7,0};
                    long temp=45;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='4')
                {
                    int a[]={4,8,2,6,0,4,8,2,6,0};
                    long temp=40;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='5')
                {
                    int a[]={5,0,5,0,5,0,5,0,5,0};
                    long temp=25;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='6')
                {
                    int a[]={6,2,8,4,0,6,2,8,4,0};
                    long temp=40;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='7')
                {
                    int a[]={7,4,1,8,5,2,9,6,3,0};
                    long temp=45;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='8')
                {
                    int a[]={8,6,4,2,0,8,6,4,2,0};
                    long temp=40;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
                else if(ch=='9')
                {
                    int a[]={9,8,7,6,5,4,3,2,1,0};
                    long temp=45;
                    long flag=n/m;
                    long x=flag/10;
                    long y=flag%10;
                    long ans=temp*x;
                    for(int i=1;i<=y;i++)
                    {
                        ans=ans+a[i-1];
                    }
                    System.out.println(ans);
                }
            }
        }
    }
}