import java.util.ArrayList;
//未完成
import java.util.Scanner;
import java.util.TreeSet;

public class Mincww {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner s = new Scanner(System.in);
		StringBuilder cww = new StringBuilder(s.next());
		s.close();
		TreeSet<Integer> clist = new TreeSet<>();
		ArrayList<Integer> wlist = new ArrayList<>();
		while(cww.indexOf("c") != -1 || cww.indexOf("w") != -1){
			int cn = cww.lastIndexOf("c");
			int wn = cww.lastIndexOf("w");
			if((cn != -1 && Math.max(cn, wn) == cn) || wn == -1){
				clist.add(cn);
				cww.delete(cn,cww.length()+1);
			}else if(cn == -1 || (wn != -1 && Math.max(cn, wn) == wn)){
				wlist.add(0,wn);
				cww.delete(wn,cww.length()+1);
			}
		}
		int count = -1;
		for(int c:clist){
			int k =0;
			for(int i = 0;i < wlist.size();i++){
				if(wlist.get(i) > c){
					k++;
					if(k == 2){
						int a = wlist.get(i)-c+1;
						if(count == -1){
							count = a;
						}else{
							count = Math.min(count, a);
						}
					}
				}
				
			}
		}
		System.out.println(count);
	}
}