import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		int ans = 1001001001;
		for(int i = 0 ; i < s.length() ; i++) {
			int w = 0;
			for(int j = i + 1 ; j < s.length() ; j++) {
				if(s.charAt(i) == 'c' && s.charAt(j) == 'w') {
					w++;
					if(w == 2) {
						ans = j - i + 1;
					}
				}
			}
		}
		System.out.println(ans == 1001001001 ? -1 : ans);
	}
}