#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
  ios::sync_with_stdio(false);
  int n, input, d, min=10000000;
  int x[100000];
  int bDiffer=0;

  cin >> n;
  for(int i=0; i<100000; ++i) x[i]=min;
  for(int i=0; i<n; ++i){
    cin >> input;
    x[i]=input;
    cout << "input :" << input << "\tnow :" << i << "\n";
  }
  cout << "input complete.\n";
  cout << "sort complete.\n";
  for(int i=0; i<n-1; ++i){
    for(int j=i+1; j<n; ++j){
      d=x[i]-x[j];
      d *= (d<0) ? -1 : 1;
      if(d!=0 && min>d){
	min=d;
	bDiffer=1;
      }
    }
  }
  cout << min*bDiffer << "\n";

  return 0;
}