import scala.math._

object Main {
  def main(args: Array[String]) = {
    val sc = new java.util.Scanner(System.in)
    val n = sc.nextInt

    val xs = (1 to n).map { _ => sc.nextInt }.toSet.toArray.sorted    
    // println(xs.mkString(" "))

    var ans = if (xs.size <= 1) 0 else xs(1) - xs(0)
    for (i <- 1 to xs.size-1) {
      ans = min(ans, xs(i) - xs(i-1))
    }
    println(ans)
  }
}