using System;
public class Program
{
public static void Main()
{ // focous on strings
// functions of it down h
Console.WriteLine("Hello World".ToUpper());
string s1 = "ra";
string s2 = "mohan";
string s3 = string.Concat(s1,s2);
// placeholder
string name = $"My full name is: {s1} {s2}";
Console.WriteLine(name);
}