#include <stdio.h>
#include <math.h>

int main(void) {
	int i, j, N, X[100001], P[1000000] = {0}, max, min, d_min, p1, p2;
	scanf("%d", &N);
	max = 0;
	min = 100000;
	for(i = 1; i <= N;i++){
		scanf("%d", &X[i]);
		P[X[i]] = 1;
		if(X[i] > max)max = X[i];
		if(X[i] < min)min = X[i];
	}
	//printf("%d %d\n", max, min);
	d_min = max - min;
	p1 = min;
	i = p1;
	while(i < max){
		j = 1;
		while(P[i + j] == 0){
			j++;
		}
		p2 = i + j;
		//printf("%d %d\n", p1, p2);
		if(p2 - p1 < d_min)d_min = p2 - p1;
		p1 = p2;
		i = p2;
	}
	printf("%d\n", d_min);
	
	return 0;
}