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

int main(){
  ios::sync_with_stdio(false);
  int n, input, min=pow(10, 6);
  vector<int> x;
  int bDiffer=0;

  cin >> n;
  for(int i=0; i<n; ++i){
    cin >> input;
    x.push_back(input);
  }
  for(int i=0; i<n; ++i){
    for(int j=i+1; j<n; ++j){
      if(x[i]!=x[j] && min > fabs(x[i]-x[j])){
	min = fabs(x[i]-x[j]);
	bDiffer=1;
      }
    }
  }
  cout << min*bDiffer << "\n";

  return 0;
}