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

int main() {
	string s;
	cin >> s;

	int c = 0,
		n = 0;
	for (int i = 0; i < s.size(); i++) {
		if (!c) {
			if (s.at(i) == 'c') {
				c = 1;
				n = i;
			}
			else {
				continue;
			}
		}
		else if (c == 1) {
			if (s.at(i) == 'w') {
				c = 2;
			}
			else {
				continue;
			}
		}
		else if (c == 2) {
			if (s.at(i) == 'w') {
				c = 3;
				n -= i;
				n = abs(n);
				n++;
				break;
			}
			else {
				continue;
			}
		}
		else {
			cout << "WA" << endl;
			return 0;
		}
	}

	if (c == 3) {
		cout << n << endl;
	}
	else {
		cout << -1 << endl;
	}
}