using System;

class Program
{
    static void Main(string[] args)
    {
        var input = Console.ReadLine();
        int len = input.Length - 1;

        for (int i = 0; i < input.Length; i++)
            if (input[i] == 'c')
                for (int j = i + 1; j < input.Length; j++)
                    if (input[j] == 'w')
                        for (int k = j + 1; k < input.Length; k++)
                            if (input[k] == 'w')
                                len = Math.Min(len, k - i + 1);

        Console.WriteLine(len == input.Length - 1 ? -1 : len);
    }
}