import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		char[] inputs = sc.next().toCharArray();
		
		int answer = Integer.MAX_VALUE;
		for(int fst = 0; fst < inputs.length; fst++){
			if(inputs[fst] != 'c'){ continue; }
			
			for(int snd = fst + 1; snd < inputs.length; snd++){
				if(inputs[snd] != 'w'){ continue; }
				
				for(int thd = snd + 1; thd < inputs.length; thd++){
					if(inputs[thd] != 'w'){ continue; }
					
					answer = Math.min(answer, (thd - fst + 1));
				}
			}
		}
		
		System.out.println(answer == Integer.MAX_VALUE ? -1 : answer);
	}

}