import java.util.Scanner;

class Question436
{
	public static void main(String[] str)
	{
	
		Scanner scan = new Scanner(System.in);
		
		String s = scan.next();
		int cnt = 0;
	
		for(int i=0;i<s.length();i++){
			if(s.charAt(i)=='w') break;
			else
				cnt++;
		}
		
		if(cnt>s.length()-cnt)
			System.out.println(s.length()-cnt);
		else
			System.out.println(cnt-1);

	}
}