#include<iostream>
#include<vector>
#include<algorithm>
#include<iomanip>
using namespace std;
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP1(i, n) for (auto i = std::decay_t<decltype(n)>{}; (i) != (n); ++(i))
#define REP2(i, l, r) for (auto i = (l); (i) != (r); ++(i))
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define REP(i, l, r) rep(i, l, r+1)
#define all(x) (x).begin(),(x).end()
#define inf 1000000000
using ll = long long;
using P = pair<int,int>;
using Graph = vector<vector<int> >;

int main() {
    // 高速化
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    // 小数点の出力桁数を指定
    cout << fixed << setprecision(10);

    // メイン
    string S;
    cin >> S;
    int ans = inf;
    rep(i, 0, S.size()) {
        rep(j, i+1, S.size()) {
            rep(k, j+1, S.size()) {
                if(S[i] == 'c' && S[j] == 'w' && S[k] == 'w') {
                    ans = min(ans, k-i+1);
                }
            }
        }
    }
    if(ans != inf) cout << ans << endl;
    else cout << -1 << endl;

    return 0;
}