#define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

int main() {
  int N; cin >> N;
  vector<int> X(0);
  for(int i = 0; i < N; i++){
    int x; cin >> x;
    bool flag = true;
    for(int j = 0; j < (int)X.size(); j++){
      if(X[j] == x) flag = false;
    }
    if(flag) X.push_back(x);
  }
  sort(X.begin(), X.end());
  if((int)X.size() >= 2){
    int ans = 1000000000;
    for(int i = 0; i < (int)X.size()-1; i++){
      ans = min(ans, X[i+1]-X[i]);
    }
    cout << ans << endl;
  }
  else cout << 0 << endl;
}