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

int main(void){
  int i, j;
  int N, X[100000];
  int min, tmp;

  min = 0x7FFFFFFF;

  scanf("%d", &N);
  for(i = 0 ; i < N; i++){
    scanf("%d", &X[i]);
    for(j = 0; j < i; j++){
      tmp = abs(X[j] - X[i]);
      if(tmp != 0){
	if(min > tmp) min = tmp;
      }
    }
  }
  if(min == 0x7FFFFFFF) printf("0\n");
  else printf("%d\n", min);
  return 0;
}