import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		String S = sc.next();
		
		char[] charS = S.toCharArray();
		
		int i = 0, cnt = 0, flag = 0, min = Integer.MAX_VALUE;
		
		while(i < charS.length) {
			if(charS[i] == 'c') {
				for(int j = i + 1; j < charS.length; j++) {
					if(charS[j] == 'w') {
						cnt++;
						
						if(cnt == 2) {
							if(j - i + 1 < min) {
								min = j - i + 1;
								charS = S.substring(j + 1).toCharArray();
								flag = 1;
							}
						} 
					}
				}
			}
		
			if(flag == 1) {
				i = 0;
				cnt = 0;
				flag = 0;
			} else {
				i++;
			}
		}
		
		if(min == Integer.MAX_VALUE) {
			System.out.println(-1);	
		} else {
			System.out.println(min);
		}
	}
}