s=gets.chomp
pos = s.split('').map.with_index{|c,i| i if c == 'c'}.compact
cww = pos.map{|p|s.slice(p,s.size-p).scan(/c[^w]*?w[^w]*?w/)}.flatten.sort{|a,b|a.size<=>b.size}
puts cww.empty? ? -1 : cww.first.size