class calc {
	public calc(){
	}

	public long add_long(long a, long b){
		return a + b ;
	}

	public double add_double(double a, double b){
		return a + b ;
	}

	public String add_string(String a, String b){
		Double ret = new Double(Double.parseDouble(a) + Double.parseDouble(b)) ;
		return ret.toString() ;
	}
}