create a C# program having 5 functions: (1) write a C# function that two parameters named va and vb. The function performs the following operations define two integer variables (named v1 and v2) and initialize them by the values from two parameters - perform the following calculations. For each operation above, if the result is greater than or equal to 100, output the result. Otherwise, only output a message telling the user that the result is less than 100. (2) write a C# function that two parameters named va and vb. The function performs the same operations as that in (1). But, this function will return the value of v2. (3) write a C# function that has two "ref" parameters named va and vb. The function performs the same operations as that in (1). But, this function will return the value of v2. (4) write a C# function that has two "out" parameters named va and vb-The function performs the same operations as that in (1). But, this function will return the value of v2. (5) Write a Main method - call the functions above