#include <bits/stdc++.h>

using namespace std;

int main() {
    string s;
    cin >> s;

    vector<int> vtC, vtW;
    for (int i = 0; i < s.length(); ++i) {
        if (s[i] == 'c') vtC.push_back(i);
        if (s[i] == 'w') vtW.push_back(i);
    }

    int ans = 200;
    for (int i = 0; i < vtC.size(); ++i) {
        for (int j = 0; j + 1 < vtW.size(); ++j) {
            if (vtW[j] > vtC[i]) {
                ans = min(ans, vtW[j + 1] - vtC[i] + 1);
                break;
            }
        }
    }

    cout << ((ans == 200) ? -1 : ans) << endl;
    return 0;
}