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

if points.length < 2
    puts 0
    return
end

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

puts dist