gets
point_array = gets.chomp.split(" ").uniq.map(&:to_i).sort
n = point_array.size - 1
min = 10000000
n.times{|i|
	judge = point_array[i + 1] - point_array[i]
	if judge < min
		min = judge
	end
}

if min == 10000000
	puts 0
else
	puts min
end