using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.IO;

​

namespace ConsoleApplication3

{

    class MainClass

    {

        public static bool isPrime(int n)

        {

            if (n == 1) return false;

            if (n == 2) return true;

            for (int i = 2; i < n; i++)

            {

                if (n % i == 0) return false;

            }

            return true;

​

        }

        //creat a function to find min and max in array

        public static void MinPrimeNumber()

        {

            //read from s.txt datas

            StreamReader sr = new StreamReader(@"C:\Users\Asus\Desktop\111.txt");

            //write a result in e.txt

            StreamWriter sw = new StreamWriter(@"C:\Users\Asus\Desktop\1.txt");

            //a string array that contains the substring of this instance 

            string[] arr = sr.ReadLine().Split();

            //the biggest variable to find min

            int min = 320000;

            //convert array to string 

            foreach (string a in arr)

            {

                //convert string to integer

                int b = int.Parse(a);

                if (b < min && isPrime(b))

                    min = b;

​

            }

​

            sw.WriteLine("The smallest Prime Number is:" + min);

            sw.Close();

            sr.Close();

​

        }

​

​

        static void Main(string[] args)

        {

            //function is called

            MinPrimeNumber();

            Console.ReadKey();

        }

    }

}