#include <bits/stdc++.h>

using namespace std;

int main()
{
    string s = "";

    for (int i = 0; i < 2; ++i) {
        string t; cin >> t;
        s += t;
    }

    string S = "o";

    for (int i = 1; i <= 14; ++i) {
        if (s.find(S) == string::npos) {
            cout << i - 1 << endl;
            return 0;
        } else {
            S += "o";
        }
    }

    cout << 14 << endl;
}