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

unsigned long cmp(const unsigned long *x, const unsigned long *y)
{
	return (*x < *y) ? -1 : (*x > *y) ? 1 : 0;
}


int main(void)
{
	unsigned long n;
	unsigned long *x;
	unsigned long tmp;
	unsigned long min = 1000001;
	int i, j;

	scanf("%lu", &n);

	x = calloc(n, sizeof(unsigned long));
	if (x == NULL)
		printf("領域確保失敗!");
	else {
		for (i = 0; i < n; i++) 
			scanf("%lu", &x[i]);

		qsort(x, n * sizeof(unsigned long) / sizeof(unsigned long), sizeof(unsigned long), (int (*)(const void *, const void *))cmp);
	
		for (i = 0; i < n; i++) {
			if (x[i + 1] - x[i] < min)
				if (x[i + 1] != x[i]) 
					min = x[i + 1] - x[i];
		}

		if (n == 1 || min == 1000001)
			printf("%lu\n", 0);
		else
			printf("%lu\n", min);

		free(x);
	}
	return 0;
}