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

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