#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define fr(i, a, b) for (int i = (a); i < (b); i++)
using namespace std;
typedef long long ll;
const ll inf = 1e9;
const ll mod = 1e9 + 7;

int main() {
    string s[2];
    cin >> s[0] >> s[1];
    string w = s[0] + s[1];

    int ans = 0;

    for (int i = 0; i < w.length(); i++) {
        for (int j = 0; j < w.length() - i; j++) {
            string sub = w.substr(i, j + 1);

            bool f = true;
            for (int k = 0; k < sub.length(); k++) {
                if (sub[k] == 'x') f = false;
            }
            if (f) ans = max(ans, (int)sub.length());
        }
    }
    cout << ans << endl;
}