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

signed main(){
  int N; cin >> N;
  vector< int > X( N );
  for( int i = 0; i < N; ++i )
    cin >> X[ i ];
  sort( X.begin(), X.end() );
  X.erase( unique( X.begin(), X.end() ), X.end() );
  int ans = ( int ) 1e9;
  for( int i = 1; i < X.size(); ++i )
    ans = min( ans, X[ i ] - X[ i - 1 ] );
  if( ans == ( int ) 1e9 )
    ans = 0;
  cout << ans << endl;
  return 0;
}