/in/Main.java:14: error: cannot find symbol
            num1=cin.nextBigInteger();
                 ^
  symbol:   variable cin
  location: class Main
/in/Main.java:15: error: cannot find symbol
            num2=cin.nextBigInteger();
                 ^
  symbol:   variable cin
  location: class Main
/in/Main.java:16: error: bad operand types for binary operator '+'
            System.out.println(num1 + num2);
                                    ^
  first type:  BigInteger
  second type: BigInteger
3 errors