#include <iostream>
#include <ctype.h>

using namespace std;

// Check all assignments of letters in C to A and B and determine
// if C is composed of A and B "shuffled together" (in order, but merged.)
string isMerge(string A, string B, string C, 
	       unsigned int a, unsigned int b, unsigned int c)
{
  // If we've looked through all of all three words
  if (a == A.size() and b == B.size() and c == C.size()) return C;

  // Give preference to A
  if (A[a] == C[c])
    {
      // Assume C[c] comes from A, so uppercase it
      C[c] = toupper(C[c]);
      // Check
      string ret = isMerge(A, B, C, a + 1, b, c + 1);
      
      // If we get a valid merge, then return it
      if (ret != "*** NOT A MERGE ***")
	return ret;
      
      // We were wrong, fix it
      C[c] = tolower(C[c]);
    }
  // Check b.  Note this isn't an else if.
  if (B[b] == C[c])
    {
      return isMerge(A, B, C, a, b + 1, c + 1);
    }

  // If we cant match the current character of C, we're done.
  return "*** NOT A MERGE ***";
}

int main()
{
  // Simplest input ever.
  string a;
  string b;
  string c;
  while (cin >> a >> b >> c)
    {
      cout << isMerge(a, b, c, 0, 0, 0) << endl;
    }
}