C# - Concatenation of string and Addition of two numbers

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string FirstName = Console.ReadLine();
            string SecondName = Console.ReadLine();
            int a = Convert.ToInt32(Console.ReadLine());
            int b = Convert.ToInt32(Console.ReadLine());

            Console.WriteLine(GetFullName(FirstName, SecondName));
            Console.WriteLine(Add(a,b));
            Console.ReadKey();

        }

        static int Add(int firstNumber, int secondNumber)
        {
            int sum = firstNumber + secondNumber;
            return sum;
        }

        static void Print()
        {
            Console.WriteLine("Hello from Print method");
        }

        static string GetFullName(string firstName, string lastName)
        {
            string fullName = firstName + " " + lastName;
            return fullName;
        }
    }
}