#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int last_digit(int n)
{
	int m = n;
	for (int i = 2; i <= m; i++)
	{
		n = n % 10;
		n = (n * m) % 10;
	}
	return n;
}

int main()
{
	FILE* f = fopen("cifra.in", "rt"), *t = fopen("cifra.out", "at");
	int T, N, S;
	fscanf(f, "%d", &T);

	for (int i = 1; i <= T; i++)
	{
		S = 0;
		fscanf(f, "%d", &N);

		for (int j = 1; j <= N; j++)
		{
			S = ((S + last_digit(j)) % 10);
		}

		fprintf(t, "%d \n", S);
		fflush(stdout);
	}
	fclose(f);
	fclose(t);

	return 0;
}