// {{{ Templates
#include <bits/stdc++.h>

#define show(x) cerr << #x << " = " << x << endl

using namespace std;
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
    os << "sz:" << v.size() << "\n[";
    for (const auto& p : v) {
        os << p << ",";
    }
    os << "]\n";
    return os;
}

template <typename S, typename T>
ostream& operator<<(ostream& os, const pair<S, T>& p)
{
    os << "(" << p.first << "," << p.second
       << ")";
    return os;
}


constexpr ll MOD = (ll)1e9 + 7LL;

template <typename T>
constexpr T INF = numeric_limits<T>::max() / 100;

// }}}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    string s;
    cin >> s;
    const int size = s.size();
    for (int l = 1; l <= size; l++) {
        for (int i = 0; i <= size - l; i++) {
            if (s[i] == 'c' and s[i + l - 1] == 'w') {
                for (int j = i + 1; j < i + l - 1; j++) {
                    if (s[j] == 'w') {
                        cout << l << endl;
                        return 0;
                    }
                }
            }
        }
    }
    cout << -1 << endl;
    return 0;
}