gets
points = gets.split.map(&:to_i).uniq.sort

if points.length < 2
    puts 0
    return
end

dist = (points[0] - points[1]).abs
for i in 0...(points.length - 1)
    if dist > (points[i] - points[i + 1]).abs
        dist = (points[i] - points[i + 1]).abs
    end
end
puts dist