import java.util.Scanner;

public class Main {

	static final int INF = Integer.MAX_VALUE;

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