#include <stdio.h>
#include <stdlib.h>

FILE *f,*g;

int ultim(int p)
{
    int i,k=1;
    for(i=1;i<=p;i++)
    {
        k=(k*p)%10;
    }
    return k;
}

int main()
{
    int T,i,k,u,N,j;

    f=fopen("cifra.in","r");
    g=fopen("cifra.out","w");

    fscanf(f,"%d",&T);
    for(j=1;j<=T;j++)
    {
        fscanf(f,"%d",&N);
        k=0;
        for(i=1;i<=N;i++)
        {
            u=ultim(i);
            k=(k+u)%10;
        }
        fprintf(g,"%d",k);
        fprintf(g,"\n");
    }

    fclose(f);
    fclose(g);
    return 0;
}