#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main(void)
{
  string s, t;
  cin >> s >> t;

  string u = s + t;
  int cur = 0, nowh = 0, maxh = 0;
  while (cur < u.size())
  {
    if (u[cur] == 'o')
    {
      while (true)
      {
        if (cur >= u.size())
        {
          maxh = max(maxh, nowh);
          nowh = 0;
          break;
        }
        else if (u[cur] == 'o')
        {
          nowh++;
        }
        else if (u[cur] != 'o')
        {
          maxh = max(maxh, nowh);
          nowh = 0;
          break;
        }
        cur++;
      }
    }
    else if (u[cur] != 'o')
    {
      cur++;
    }
  }

  cout << maxh << endl;
  return 0;
}