#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

unsigned long long last_digit(unsigned long long n)
{
	n = n % 10;
	switch (n) 
	{
	case 1: return 1; break;
	case 2: return 4; break;
	case 3: return 7; break;
	case 4: return 6; break;
	case 5: return 5; break;
	case 6: return 6; break;
	case 7: return 3; break;
	case 8: return 6; break;
	case 9: return 9; break;
	case 0: return 0; break;
	
	default: return 0;
	};
}

int main()
{
	FILE* f = fopen("cifra.in", "rt"), *t = fopen("cifra.out", "at");
	unsigned long long T, N, v[100000];
	char c[10000];
	fgets(c, 10001, f);
	sscanf(c, "%llu", &T);

	v[0] = 0;

	for (int i = 1; i < 10001; i++)
		v[i] = ((v[i - 1] + last_digit(i)) % 10);

	for (int i = 1; i <= T; i++)
	{
		if (fgets(c, 10001, f) == EOF)
			break;

		sscanf(c, "%llu", &N);
		fprintf(t, "%llu\n", v[N]);
		fflush(stdout);
		
	}

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