#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    string s;
    cin >> s;
    vector<ll> cidx, widx;
    rep(i, len(s)) {
        if (s[i] == 'c') {
            cidx.push_back(i);
        }
        else if (s[i] == 'w') {
            widx.push_back(i);
        }
    }
    ll ans = LONG_LONG_MAX;
    rep(i, sz(cidx)) {
        auto it = lower_bound(all(widx), cidx[i]);
        ll cnt = sz(widx) - (it - widx.begin());
        if (cnt < 2) continue;
        it++;
        ll size = *it - cidx[i] + 1;
        ans = min(ans, size);
    }
    if (ans == LONG_LONG_MAX) ans = -1;
    cout << ans << endl;
    return 0;
}