#include <bits/stdc++.h>
using namespace std;

int main(void) {
	string s;
	cin >> s;
	bool flag = 0;
	int count = 0;
	int now;
	for (int i = 0; i < s.length(); ++i) {
		if (s[i] == 'c') {
			now=i;
			while (i < s.length()) {
				i++;
				if(s[i]=='w'&&count==0){
					count++;
				}else if(s[i]=='w'&&count==1){
					cout<<i-now<<endl;
					return 0;
				}
			}
		}
	}
	cout<<-1<<endl;
}