#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

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