#include <stdio.h>

int main(void)
{
	int N, tmp[6] = {1, 4, 2, 8, 5, 7}, i;
	scanf("%d", &N);
	if (N == 0) puts("0");
	else {
		printf("0.");
		for (i = 0; i < N / 6; ++i) printf("142857");
		for (i = 0; i < N % 6; ++i) printf("%d", tmp[i]);
	}
	return 0;
}