using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;

class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        string inpt = Reader.ReadLine();
        
        int ans = int.MaxValue;
        for(int i=0; i<inpt.Length; i++) {
            if(inpt[i] == 'c') {
                int wCOunt = 0;
                for(int j=i+1; j<inpt.Length; j++) {
                    if(inpt[j] == 'w') {
                        wCOunt++;
                        if(wCOunt == 2) {
                            ans = Math.Min(ans, j-i+1);
                            break;
                        }
                    }
                }
            }
        }
        if(ans == int.MaxValue) {
            ans = -1;
        }
        Console.WriteLine(ans);


    }
    


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"



wachiwachi




";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}