#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <numeric>
#define rep(x, to) for (int x = 0; x < (to); x++)
#define REP(x, a, to) for (int x = (a); x < (to); x++)
#define foreach(itr, x) for (typeof((x).begin()) itr = (x).begin(); itr != (x).end(); itr++)

using namespace std;

typedef long long ll;
typedef pair<int, int> PII;
typedef pair<long, long> PLL;

string s, t;
int tmp, ans;

int main() {
	cin >> s;
	cin >> t;
	s += t;
	s += 'x';
	rep(i, s.size() - 1) {
		if (s[i] == 'o' && s[i+1] == 'o') {
			tmp++;
		} else if (s[i] == 'o' && s[i+1] == 'x') {
			tmp++;
			ans = max(ans, tmp);
			tmp = 0;
		}
	}
	cout << ans << endl;
	return 0;
}