using System;
using System.Collections.Generic;

class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("ilovechiwawa");
            //6
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("wachiwachi");
            //-1
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("chiwaaaaaaamikawayadeeeeesu");
            //16
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        string S = InputList[0];

        bool FoundAnswer = false;
        int MinLength = int.MaxValue;
        for (int I = 0; I <= S.Length - 1; I++) {
            if (S[I] != 'c') continue;
            bool WillBreak = false;
            for (int J = I + 1; J <= S.Length - 1; J++) {
                if (S[J] != 'w') continue;
                for (int K = J + 1; K <= S.Length - 1; K++) {
                    if (S[K] != 'w') continue;
                    FoundAnswer = true;
                    if (K - I + 1 < MinLength) {
                        MinLength = K - I + 1;
                        WillBreak = true;
                        break;
                    }
                }
                if (WillBreak) break;
            }
        }
        Console.WriteLine(FoundAnswer ? MinLength : -1);
    }
}