#include <bits/stdc++.h>
#define FOR(i,bg,ed) for(ll i=(bg);i<(ed);i++)
#define REP(i,n) FOR(i,0,n)
#define MOD 1000000007
#define int long long
using namespace std;
typedef long long ll;
const int INF = 1e9;



signed main()
{
    string S;

    cin >> S;
    int ans = 999;
    REP(i,S.length()) {
        if (S[i] == 'c') {
            int cnt = 0;
            for (int j=i+1; j<S.length(); j++) {
                if (S[j] == 'w') cnt++;
                if (cnt == 2) {
                    ans = min(ans, j - i + 1);
                }
            }
        }
    }

    cout << (ans == 999 ? -1 : ans) << endl;
}