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