n=gets.to_i
retsu = [n]
sa = [n]
retsu = gets.split(" ").map(&:to_s)
retsu=retsu.uniq
retsu.sort!
len = retsu.length
sa[len-1] = (retsu[len-1].to_i-retsu[0].to_i).abs
for i in 0..(len-2)
  sa[i] = (retsu[i+1].to_i-retsu[i].to_i).abs
end
sa.sort!
puts sa[0]