/* Solving the maximum subsequence problem with Step 1 of dynamic programming. */

#include <iostream>
#include <string>
#include <cstdlib>
using namespace std;

class Subseq {
  public:
    int MCS(const string &s1, const string &s2);
};
  
int Subseq::MCS(const string &s1, const string &s2)
{
  int r1, r2;

  /* Base case -- if either string is empty, return 0. */

  if (s1.size() == 0 || s2.size() == 0) return 0;

  /* If the first characters of the two strings equal each other,
     then the answer is one plus the MCS of the two string with
     the first characters chopped off. */

  if (s1[0] == s2[0]) return 1 + MCS(s1.substr(1), s2.substr(1));

  /* Otherwise, the answer is either:
       - r1: The MCS of the 1st string, and the 2nd string without its first character
       - r2: The MCS of the 2nd string, and the 1st string without its first character
   */   

  r1 = MCS(s1, s2.substr(1));
  r2 = MCS(s1.substr(1), s2);
  return (r1 > r2) ? r1 : r2;   // Return the maximum of r1 and r2.
}

int main(int argc, char **argv)
{
  string s1, s2;
  Subseq s;

  if (argc != 3) { cerr << "usage: subseq s1 s2\n"; exit(1); }

  s1 = argv[1];
  s2 = argv[2];

  cout << s.MCS(s1, s2) << endl;
  return 0;
}