#include <stdio.h>
#include <stdlib.h>
int c(const void *a,const void *b){return *(int*)a-*(int*)b;}
int main(){
int m,a[100000],s,n=0;
scanf("%d",&m);s=m;
while(s)scanf("%d",a+m-s--);
qsort(a,m,4,c);
while(--m)if(s=a[m]-a[m-1])n=!n||s<n?s:n;
printf("%d\n",n);
return 0;
}