<?php
$N = trim(fgets(STDIN));
$X = explode(" ", trim(fgets(STDIN)));
sort($X);
$ans = 10000000;
$small = $X[0];
for($i = 0; $i < $N; $i++) {
  $x = $X[$i];
  if($x > $small) {
    $ans = min($ans, $x - $small);
    $small = $x;
  }
}
if($ans == 10000000) $ans = 0;
print($ans);
?>