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

int ultima_cifra(int x)
{
    int nr = 1;
    int u_cifr;
    for (int i = 0; i < x; i++)
    {
        nr = nr * x;
        u_cifr = nr % 10;
        nr = u_cifr;
    }
    return nr;

}

int main()
{
    int x;
    int n;
    FILE *in = fopen("cifra.in", "rt");
    FILE *out = fopen("cifra.out", "wt");
    int sum = 0;
    fscanf(in, "%d", &n);

    for (int k = 0; k < n; k++)
    {
        fscanf(in, "%d", &x);
        //printf("c========%c\n", x);

        for (int i = 1; i <= x; i++) {
            sum = sum + ultima_cifra(i);
            if(sum > 10) sum = sum % 10;
            printf("sum:%d\n", sum);
        }
       printf("\n");
        fprintf(out, "%d\n", sum);
        sum = 0;
    }
    fclose(in);
    fclose(out);
    return 0;
}