Problem:
Score : 100 points

Problem Statement

You will turn on the air conditioner if, and only if, the temperature of the room is 30 degrees Celsius or above.

The current temperature of the room is X degrees Celsius. Will you turn on the air conditioner?

Constraints

-40 \leq X \leq 40

X is an integer.

Input

Input is given from Standard Input in the following format:

X

Output

Print Yes if you will turn on the air conditioner; print No otherwise.

Sample Input 1

25

Sample Output 1

No

Sample Input 2

30

Sample Output 2

Yes

Solution in C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Numerics;
using System.Linq;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace debug
{
    class main
    {
        static void Main(string[] args)
        {
            //問題クラスを展開
            ProgramA a = new ProgramA();
            a.main();//実行する

        }

    }
    //ABC170
    class ProgramA
    {
        public void main()
        {
            //入力
            int x = int.Parse(Console.ReadLine());


            if (x >= 30)
                Console.WriteLine("Yes");
            else
                Console.WriteLine("No");

        }
    }

    class ProgramB
    {
        public void main()
        {
            //入力
            int n = int.Parse(Console.ReadLine());
            string[] s = Console.ReadLine().Split(' ');

            int count = 0;
            for(int i = 0; i < n;i = i + 2)
            {
                if (int.Parse(s[i]) % 2 == 1)
                    count++;
            }

            Console.WriteLine(count);

        }
    }

    class ProgramC
    {
        public void main()
        {

            //入力
            int n = int.Parse(Console.ReadLine());

            int[] ans = new int[n];

            //(x,y,z)組み合わせを全探索最大でも1-100までの間しかないことに注目
            for(int x = 1;x <= 100;x++)
                for (int y = 1; y <= 100; y++)
                    for (int z = 1; z <= 100; z++)
                    {
                        long temp = x * x + y * y + z * z + x * y + x * z + y * z;
                        if (temp <= n)
                            ans[temp - 1]++;
                    }

            for(int i = 0;i < n;i++)
                Console.WriteLine(ans[i]);



        }
    }

    class ProgramD
    {
        public void main()
        {

            //入力
            long n = long.Parse(Console.ReadLine());
            string s = Console.ReadLine();

            int count = 0;
            long num = 0;
            long num2 = 0;
            for (int i = 0; i < n; i++)
            {
                if (s[i] == '1')
                    count++;
            }

            if (count == 0)
            {
                for (int i = 0; i < n; i++)
                    Console.WriteLine("1");
                return;
            }

            if (count == 1)
            {
                if (s[(int)n - 1] == '1')
                {
                    for (int i = 0; i < n; i++)
                    {
                        if (i == n - 1)
                            Console.WriteLine("0");
                        else
                            Console.WriteLine("2");
                    }
                }
                else
                {
                    for (int i = 0; i < n; i++)
                    {
                        if (s[i] == '1')
                            Console.WriteLine("0");
                        else if(i == n -1)
                            Console.WriteLine("2");
                        else
                            Console.WriteLine("1");
                    }
                }
                return;
            }

            for (int i = 0; i < n; i++)
            {
                if (s[i] == '1')
                {
                    num += modpow(2, n - 1 - i, count -1);
                    num2 += modpow(2, n - 1 - i, count + 1);
                }
            }

            for (int i = 0; i < n; i++)
            {
                long temp = 0;

                if (s[i] == '1')
                {
                    temp = num;
                    temp -= modpow(2, n - 1 - i, count - 1);
                    temp %= count - 1;
                }
                else
                {
                    temp = num2;
                    temp += modpow(2, n - 1 - i, count + 1);
                    temp %= count + 1;
                }

                long ans = 1;

                while(temp != 0)
                {
                    long t = 0;
                    long t2 = temp;
                    while (temp != 0)
                    {
                        t += temp % 2;
                        temp /= 2;
                    }

                    temp = t2 % t;
                    ans++;

                }

                Console.WriteLine(ans);
            }

        }

        static long modpow(long a, long n, long MOD)
        {
            if (n == 0)
                return 1;
            if (n % 2 == 0)
            {
                long temp = modpow(a, n / 2, MOD);
                return temp * temp % MOD;
            }

            return a * modpow(a, n - 1, MOD) % MOD;
        }
    }

    class ProgramE
    {

        public void main()
        {
            //入力
            int t = int.Parse(Console.ReadLine());


            for(int x = 0;x < t;x++)
            {
                int n = int.Parse(Console.ReadLine());
                for(int i = 0;i < n;i++)
                {

                }

            }


        }


    }

}