package me.yukicoder.lv1;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class No0345 {
	public static void main(String[] args) {
		try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
			String str = br.readLine();
			int ans = -1;
			int idx = str.indexOf("c");

			if (idx != -1) {
				String str1 = str.substring(idx, str.lastIndexOf("w") + 1);
				Matcher m = Pattern.compile("c.*w.*w").matcher(str1);
				ans = m.matches() ? m.end() : ans;
			}
			System.out.println(ans);

		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}