n = gets.to_i
xs = gets.split(' ').map(&:to_i)

xs.sort!.uniq!
size = xs.size
if size <= 1
  puts 0
  exit
end

a = 9999999999
(size - 1).downto(1) do |i|
  d = (xs[i] - xs[i - 1]).abs
  a = d if a > d
end

puts a