#include <bits/stdc++.h>
using namespace std;

int main(){
    string S; cin >> S;
    int N = S.size();
    int ans = 109;
    for(int i = 0; i < N - 2; ++i){
        for(int j = i + 1; j < N - 1; ++j){
            for(int k = j + 1; k < N; ++k){
                if(S[i] == 'c'&&S[j] == 'w'&&S[k] == 'w'){
                    ans = min(ans, k - i + 1);
                }
            }
        }
    }
    if(ans == 109) cout << -1 << endl;
    else cout << ans << endl;
}