s = gets.chomp

lens = []
for i in 0..(s.length-3) do
  next unless s[i] == "c"
  for j in (i+1)..(s.length-2) do
    next unless s[j] == "w"
    for k in (j+1)..(s.length-1) do
       next unless s[k] == "w"
       lens << k - i + 1
    end
  end
end

puts lens.size > 0 ? lens.min : -1