#include<iostream>
#include<string>
using namespace std;
int main() {
	string s; cin >> s; int ans = s.length() + 1;
	for (int i = 0; i < s.length() - 2; i++) {
		for (int j = 2; i + j < s.length(); j++) {
			if (s[i] == 'c'&&s[i + j] == 'w') {
				for (int k = i + 1; k < i + j; k++) {
					if (s[k] == 'w') {
						ans = min(ans, j + 1);
						break;
					}
				}
			}
		}
	}
	if (ans == s.length() + 1) {
		cout << -1 << endl;
	}
	else {
		cout << ans << endl;
	}
}