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

#define INF	(9999999)

int compare_int( const void*a, const void*b){
	int ta = *(int*)a;
	int tb = *(int*)b;
	if(ta < tb){
		return -1;
	}else if(ta > tb){
		return 1;
	}
	
	return 0;
}

int main(void){
	int i,n;
	int x[100100];
	int minDis = INF;
	
	scanf("%d", &n);
	for(i=0;i<n;i++){
		scanf("%d", &x[i]);
	}
	
	qsort(x, n, sizeof(int), compare_int);
	
	for(i=1;i<n-1;i++){
		int dis = x[i] - x[i-1];
		if(dis != 0 && dis < minDis ){
			minDis = dis;
		}
		dis = x[i+1] - x[i];
		if(dis != 0 && dis < minDis ){
			minDis = dis;
		}
	}
	
	if(minDis == INF){
		minDis = 0;
	}
	
	printf("%d\n", minDis);
	return 0;
}