#!/bin/ruby

n = gets.strip.to_i
a = gets.strip
a = a.split(' ').map(&:to_i)
# your code goes here

def find_min_diff(n, a)
  min = nil
  a.sort!
  a[0...-1].each.with_index do |num, idx|
    diff = (num - a[idx + 1]).abs
    return 0 if diff.zero?
    min = diff if min.nil? || min > diff
  end
  min
end



p find_min_diff(n, a)