n = gets.to_i
x = gets.split.map(&:to_i).sort
min = 10 ** 7
(n - 1).times do |i|
    d = x[i + 1] - x[i]
    if d == 0
        next 
    end
    if d < min
        min = d
    end
end
if min < 10 ** 7
    puts min
else
    puts 0
end