s = gets.chomp
n = s.size
mi = n +1
for i in (0..n)
  if s[i]=="c"
    cou = 0
    for j in (i+1..n)
      if s[j]=="w"
        cou+=1
      end
      if cou == 2
        (j-i+1) < mi ? mi = j-i+1 : mi
        break
      end
    end
  end 
end 
puts mi != n+1 ? mi : -1