#include <iostream>

int main()
{
    char s[101];
    std::cin >> s;
    
    int ret = 999;
    int count;
    int w;
    for(int i = 0; s[i]; i++)
    {
        if(s[i] == 'c')
        {
            count = 1;
            w = 0;
            for(int j = i + 1; s[j]; j++)
            {
                count++;
                if(s[j] == 'w')
                    w++;
                    
                if(w == 2)
                {
                    ret = (ret < count)? ret:count;
                    break;
                }
            }
        }
    }
    
    ret = (ret == 999)? -1:ret;

    std::cout << ret << std::endl;
    
    return 0;
}