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

int main(){
    string S; cin >> S;
    int wcnt = 0, cstate = -1;
    for(int i = 0; i < S.size(); ++i){
        if(S[i] == 'c') cstate = i;
        if(cstate != -1&&S[i] == 'w'){
            ++wcnt;
        }
        if(wcnt == 2){
            cout << i - cstate + 1 << endl;
            exit(0);
        }
    }
    cout << -1 << endl;
}