import java.util.Scanner;

public class Main {

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