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

namespace ConsoleApplication6
{
    class Program
    {
        static void Main(string[] args)
        {
            var s = Console.ReadLine();
            var cww = s.Aggregate(new { Cwws = new List<Cww>(), Index = 0 }, (l, x) =>
            {
                foreach (var item in l.Cwws)
                {
                    item.Push(l.Index, x);
                }

                if (x == 'c')
                {
                    l.Cwws.Add(new Cww(l.Index));
                }
                return new { Cwws = l.Cwws, Index = l.Index + 1 };
            })
            .Cwws
            .Where(x => x.IsFinish)
            .OrderBy(x => x.Length)
            .FirstOrDefault();
            Console.WriteLine(cww?.Length ?? -1);
        }
    }

    class Cww
    {
        private bool FindFirstW { get; set; }
        public int StartIndex { get; }
        public int? Length { get; private set; }

        public bool IsFinish => this.Length != null;

        public Cww(int startIndex)
        {
            this.StartIndex = startIndex;
        }

        public void Push(int index, char w)
        {
            if (this.IsFinish) { return; }
            if (w != 'w') { return; }

            if (this.FindFirstW)
            {
                this.Length = index - this.StartIndex + 1;
            }
            else
            {
                this.FindFirstW = true;
            }
        }
    }
}