#include <iostream>
#include <string>

using namespace std;

const int inf = 1e9;

int main() {
	string s;
	cin >> s;
	int ans = inf;
	for (int i = 0; i < s.size(); i++) {
		if (s[i] == 'c') {
			int len = inf;
			int w = 0;
			for (int j = i + 1; j < s.size(); j++) {
				if (s[j] == 'w') {
					w++;
					if (w == 2) {
						len = j - i + 1;
						break;;
					}
				}
			}
			ans = min(ans, len);
		}
	}
	if (ans == inf) {
		ans = -1;
	}
	cout << ans << endl;
	return 0;
}