#include <iostream>
#include <string>
using namespace std;

int main() {
	string s;
	cin >> s;
	int cnt = 0, min = 1000;
	for (int i = 0;i<s.size();i++) {
		if (s[i] == 'c') {
			cnt = 1;
			for (int j = i;j<s.size();j++) {
				if (s[j] == 'w') {
					for (int k = j + 1;k<s.size();k++) {
						if (s[k] == 'w') {
							cnt++;
							if (cnt < min)
								min = cnt;
						}
						else
							cnt++;
					}
				}
				else
					cnt++;
			}
		}
	}
	if (min < 1000)
		cout << min << endl;
	else
		cout << -1 << endl;
}