s = gets.chomp.chars
c1 = nil
w1, w2 = nil, nil
s.each_with_index do |ss, i|
  if c1.nil? && ss == 'c'
    c1 = i
  elsif c1 && w1.nil? && ss == 'w'
    w1 = i
  elsif c1 && w2.nil? && ss == 'w'
    w2 = i
  end
end
puts w2.nil? ? -1 : w2 - c1 + 1