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

namespace yukikoda
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            if (s.Length < 3)
            {
                Console.WriteLine("-1");
                return;
            }

            int i = 0;
            int min = int.MaxValue;

            while (s.IndexOf('c', i) != -1)
            {
                i = s.IndexOf('c', i) + 1;
                if (i == s.Length - 1) break;

                int wc = 0;

                for (int j = i + 1; j < s.Length - 1; j++)
                {
                    if (s[j] == 'w')
                    {
                        wc++;
                        if (wc == 2)
                        {
                            if (min > j + 2 - i)
                            {
                                min = j + 2 - i;
                                break;
                            }
                        }
                    }
                }


            }

            if (min == int.MaxValue)
            {
                min = -1;
            }
            Console.WriteLine(min);
        }
    }
}