public int stringMatch(String a, String b) {
   int checkNum=0;
   String shorter= "";
   if (a.length()<= b.length()){
      shorter= a;
   }
   else{
      shorter= b;
   }

   for (int i=0; i<shorter.length()-1; i++){
      if( a.substring(i,i+2).equals(b.substring(i,i+2))){
         checkNum++;
      }
   }
   return checkNum;
}