test_case = gets.chomp.to_i
list = gets.chomp.split.map(&:to_i).uniq.sort!
distance = 1000000

for i in 0...list.length - 1 do
	distance = (list[i + 1] - list[i]).abs if distance > (list[i + 1] - list[i]).abs
end
distance = 0 if list.length == 1
puts distance