#!/bin/ruby

n = gets.strip.to_i
a = gets.strip
a = a.split(' ').map(&:to_i).sort.reverse
# your code goes here
r = a[0] - a[1]
(0..a.size-2).each do |i| 
    aux = a[i]-a[i+1]
    r = aux if aux < r
    break if r == 0
end
puts r