#include<stdio.h>
#define INPUT "cifra.in"
#define OUTPUT "cifra.out"
int main ()
{
    freopen (INPUT,"r",stdin);
    freopen (OUTPUT,"w",stdout);
    int n,s,j,q,i,a;
    long nr;
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
                     scanf("%ld",&nr);
                     s=0;
                     for(j=1;j<=nr;j++)
                     {
                                       if((j*j)%10==j)
                                       s+=j;
                                       else
                                       {
                                           a=j%10;
                                           
                                           for(q=1;q<j;q++)
                                           {
                                                           a*=(j%10);
                                           }
                                       s+=a;
                                       }
                     }
    printf("%d\n",s%10);
    }
    return 0;
}