strs = gets.chomp.scan(/c.*w.*w/)
if strs.length == 0
    puts "-1"
else
    c,w1,w2 = false, false, false
    count = 0
    strs[0].chars do |s|
        count += 1
        if s == "c"
            c = true 
        elsif s == "w" and not w1
            w1 = true 
        elsif s == "w" and w1
            w2 = true
        end
        if c and w1 and w2
            puts count
            break
        end
    end
end