n = gets.to_i
a = gets.split.map(&:to_i).sort

ans = []

n.times do |i|
    next if i == 0 || i == n-1
    b = a[i] - a[i-1]
    c = a[i+1] - a[i]
    ans << b if b != 0
    ans << c if c != 0
end
puts ans.min