#include <iostream>
using namespace std;
int main(void) {
	string s;
	cin >> s;
	int INF = 1e9;
	int ans = INF;
	for (int i = 0; i < s.size(); ++i) {
		if (s[i] == 'c') {
			for (int j = i + 1; j < s.size(); ++j) {
				if (s[j] == 'w') {
					for (int k = j + 1; k < s.size(); ++k) {
						if (s[k] == 'w') {
							ans = min(ans, k - i + 1);
							break;
						}
					}
				}
			}
		}
	}
	if (ans == INF) ans = -1;
	cout << ans << endl;
	return 0;
}