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

int main(void)
{
	int n, x[1000000], i, j, m = 1000000, t;
	scanf("%d", &n);
	for (i = 0; i < n; i++) scanf("%d", &x[i]);
	for (i = 0; i < n - 1; i++) {
		for (j = i + 1; j < n; j++) {
			t = abs(x[i] - x[j]);
			t < m&&t != 0 ? m = t : 0;
		}
	}
	printf("%d\n", m);
	return 0;
}