using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Lab4
{
internal class Lab4
{
static void Main(string[] args)
{
//---------Integer Operations---------
Console.Write("Enter a = ");
int a = int.Parse(Console.ReadLine());
Console.Write("Enter b = ");
int b = int.Parse(Console.ReadLine());
Console.Write("Enter c = ");
int c = int.Parse(Console.ReadLine());
Console.Write("Enter d = ");
int d = int.Parse(Console.ReadLine());
int result;
result = ((a + b) / c) * d;
Console.WriteLine("The result: {0}", result);
//----------Circle Area----------
Console.Write("Enter radius r: ");
double r = double.Parse(Console.ReadLine());
double circleArea = r * r * 3.141592653589;
Console.WriteLine("The area of circle is "+ circleArea);
//---------Exact Sum of Real Numbers----------
Console.Write("Enter n: ");
int n = int.Parse(Console.ReadLine());
decimal[] arr = new decimal[n];
decimal sum = 0;
for (int i = 0; i < n; i++)
{
Console.Write("Enter the number {0}: ",i + 1);
arr[i] = decimal.Parse(Console.ReadLine());
sum = sum + arr[i];
}
