import java.util.ArrayList;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        
        Scanner scanner = new Scanner(System.in);
        
        String s = scanner.next();
        
        char c;
        
        ArrayList<Integer> list = new ArrayList<>();
        
        for(int i=0;i<s.length();i++){
            c = s.charAt(i);
            if(c == 'c'){
                list.add(i);
            }
        }
        
        int w1;
        int w2;
        
        int min = -1;
        
        for(int i=0;i<list.size();i++){
            
            w1 = s.indexOf("w",list.get(i));
            w2 = s.indexOf("w",w1+1);

            if(w1 != -1 && w2 != -1){
                if(min == -1){
                    min = w2 - (list.get(i) - 1);
                }else if(min > w2 - list.get(i) - 1){
                    min = w2 - (list.get(i) - 1);
                }
            }
            
        }
        
        System.out.println(min);
    }
    
}