using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program
    {
        private static Regex _regex = new Regex("c.*?w.*?w");

        static void Main(string[] args)
        {
            var target = Console.ReadLine();
            var r = _regex.Matches(target);

            if (r == null)
            {
                Console.WriteLine("-1");
                return;
            }
            var i = 101;
            foreach (Match c in r)
            {
                if (i > c.Length) i = c.MatcheEx(_regex).Value.Length;
            }
            Console.WriteLine(i);

            Console.ReadKey();
        }
    }

    public static class MatchEX
    {
        public static Match MatcheEx(this Match match, Regex regex)
        {
            var target = match.Value.Substring(1);
            var search = regex.Matches(target);

            if(search.Count == 0)
            {
                return match;
            }
            else if (search.Count == 1)
            {
                return search[0].MatcheEx(regex);
            }
            else
            {
                throw new Exception("too match");
            }
        }
    }
}