package no345;

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 min = Integer.MAX_VALUE;
		for(int i=0;i<n;i++) {
			for(int j=i;j<n;j++) {
				String t = s.substring(i, j + 1);
				if (isChiwawaSequence(t)) {
					min = Math.min(min, j - i + 1);
				}
			}
		}
		System.out.println(min == Integer.MAX_VALUE ? -1 : min);
	}
	
	public static boolean isChiwawaSequence(String s) {
		int state = 0;
		for(int i=0;i<s.length();i++) {
			if (state == 0 && s.charAt(i) == 'c') {
				state++;
			}else if(state >= 1 && s.charAt(i) == 'w') {
				state++;
			}
		}
		return state >= 3;
	}

}