#include <iostream>
#include <string>
using namespace std;

int main(){
    string cww; cin >> cww;
    int len = cww.size();
    int count;
    for(int i = 0; i < len-2; i++){
        if(count == 2) break;
        count = 0;
        if(cww[i] == 'c'){
            for(int j = i+1; j < len-1; j++){
                if(cww[j] == 'w'){
                    count += 1;
                    if(count == 2){
                        for(int k = 0; k < j ; k++) if(cww[k] == 'c') i = k;
                        cout << j - i + 1 << endl;
                        break;
                    }
                }
            }
        }
    }
    if(count != 2) cout << -1 << endl;
    return 0;
}