public String conCat(String a, String b) {
      String str;
      if(a.length()==0 | b.length()==0){
          str = a+b;
      }
      else if(a.substring(a.length()-1, a.length()) == (b.substring(0,1))){
          str = a + b.substring(2,b.length());
      }
      else{
          str =a+b;
      }
      return str;
}

public class conCat {
/*    public String a;
    public String b;*/

/*    public conCat(String str1, String str2){
        a = str1;
        b = str2;
    }*/

/*    public String getA(){
        return a;
    }

    public String getB(){
        return b;
    }*/

    public String conCat2(String a, String b) {
        String str="";
        if(a.length() ==0 | b.length() ==0){
            str=a+b;
        }
        else{
            if(a.substring(a.length()-1, a.length()).equals(b.substring(0,1))){
                str = a + b.substring(1, b.length());
            }
            else{
                str=a+b;
            }
        }

        return str;
    }
}


public class main {

    public static void main(String[] args){
        conCat[] result = new conCat[6];
        result[0] = new conCat2("abc", "cat");
        result[1] = new conCat2("dog", "cat");
        result[2] = new conCat2("abc", "");
        result[3] = new conCat2("", "cat");
        result[4] = new conCat2("pig", "g");
        result[5] = new conCat2("pig", "doggy");

    conCat our = new conCat();
    String outs = our.conCat2("abc", "cat");
    System.out.println(outs);
/*
        for(conCat e: result){
            result.conCat2(e.getA(), e.getB());
        }*/

    }


}