import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String S = scan.next();
		scan.close();
		int cnt1 = 0;
		int cnt2 = 0;

		for(int i = 0; i < S.length(); i++) {
			char c = S.charAt(i);
			if(c == 'w') {
				cnt1 = i;
				cnt2 = S.length() - cnt1;
				break;
			}
		}
		if(cnt1 - 1 >= cnt2) {
			System.out.println(cnt2);
		}else {
			System.out.println(cnt1 - 1);
		}
	}
}