#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
using ll = long long;
using namespace std;
const int INF = 1e9;

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

    int ans = INF;
    for (int i = 0; i < s.size(); ++i) {
        for (int j = i + 1; j < s.size(); ++j) {
            for (int k = j + 1; k < s.size(); ++k) {
                if (s[i] == 'c' && s[j] == 'w' && s[k] == 'w')
                    ans = min(ans, k - i + 1);
            }
        }
    }

    cout << (ans == INF ? -1 : ans) << endl;

    return 0;
}