#include <iostream>
using namespace std;

const int kINF = 1 << 25;

string S;

void Solve() {
    int answer = kINF;
    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') {
                            answer = min(answer, k - i + 1);
                        }
                    }
                }
            }
        }
    }
    if (answer < kINF) cout << answer << endl;
    else cout << -1 << endl;
}

int main() {
    cin >> S;

    Solve();

    return 0;
}