#include<stdio.h>
#include<stdlib.h>
int c(const void*a,const void*b){return*(int*)a-*(int*)b;}
int main(){
int m,a[1<<17],s=0,n=0;scanf("%d",&m);
while(s<m)scanf("%d",a+s++);qsort(a,m,4,c);
while(--m)if(s=a[m]-a[m-1])n=!n||s<n?s:n;printf("%d",n);
return 0;
}