import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No00000345_Main {
	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	public static void main(String[] args) throws IOException {
		String s = br.readLine();
		int minLen = 101;
		for(int i = 0; i < s.length(); i++) {
			char c = s.charAt(i);
			if(c == 'c') {
				int wCnt = 0;
				for(int j = i; j < s.length(); j++) {
					char cSub = s.charAt(j);
					if(cSub == 'w') wCnt++;
					if(wCnt == 2 &&  j - i + 1 < minLen) {
						minLen = j - i + 1;
						break;
					}
				}
			}
		}
		System.out.println(	minLen == 101 ? -1 : minLen);
	}
}