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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.NoSuchElementException;


public class Main {
	public static void main(String[] args) {
		for(int i=0;i<1;i++) {
			slover();
			out.flush();
		}
	}
	static FastScanner sc = new FastScanner();
	static PrintWriter out = new PrintWriter(System.out);
	//StringBuffer S = new StringBuffer(sc.next());
		//String hoge2 = str.reverse().toString();
		//map.containsKey(A)
		//Map<Integer, Integer> map = new HashMap<Integer, Integer>(N);
		/*for ( キーのデータ型 key : マップの名前.keySet() ) {
			データのデータ型 data = マップの名前.get( key );

			// keyやdataを使った処理;
		}*/
		//int i = Integer.parseInt(s);
		//Queue<String> qq=new ArrayDeque<>(); //add,poll,peek BFSは前から実行される
		//Deque<String> dd=new ArrayDeque<>();//push後ろに入れる,poll(pop)後ろからとる,peek addは先頭に入るからバグ注意
		//stackdfsは後ろから実行される
		//ArrayList<Integer> cc = new ArrayList<>(N);
		//cc.contains(tmp)
		//Arrays.asList(c).contains("a")
		//list.set(1,"walk");//1 1 2 3 5
		//PriorityQueue<Integer> r=new PriorityQueue<Integer>();//add poll

		private static int INF =1000000007;



		private static class D{
		
			ArrayList<Integer> X=new ArrayList<>();
			ArrayList<Integer> Y=new ArrayList<>();
			int t=0;
			int index=0;
			D(ArrayList<Integer> X,ArrayList<Integer> Y,int t,int index){
				this.X=X;;
				this.Y=Y;
				this.t=t;
				this.index=index;
			}

		}



	//Set<Long> a=new HashSet<Long>();
	
	
	
	//Integer.toBinaryString(i);
	//Integer.toString(i, 2);
//	//Integer.parseInt(bin, 2);
	//bitset
	private static int mod=1000000007;
	private static int slover()   {
		
		
		int x=sc.nextInt();
		if(x>=30)p("Yes");
		else p("No");
		
		
		
		
		
		
		return 0;
	}
	//速度が足りないときは、前計算を1回だけにしたり、longをintに変えたりするといい
	private static long modNcR2(int n,int r) {
		long x_b=1;
		
		for(int i=0;i<r;i++) {
			x_b*=(n-i);
			x_b%=mod;
		}
		
		long y=1;
		for(int i=1;i<=r;i++) {
			y*=i;
			y%=mod;
			//nPrにr!%modの逆元を掛ける
		}
		return  (x_b*modPow((int) y,mod-2,mod)%mod);
		
	}
	private static int modPow2(String S,int mod) {
		//iのt乗をO(log t)で返す
		int a=2;
		int res=1;
		int N=S.length()-1;
		for(int i=0;i<S.length();i++) {
			if(S.charAt(N-i)=='1') {
				res=res*a%mod;
			}
			a=a*a%mod;
		}
		return res;
	}
	

	private static ArrayList<Long> divisors2(long t) {
		ArrayList<Long> c=new ArrayList<>();
		for(int i=1;i*i<=t;i++) {
			if(t%i==0) {
				if(i*i!=t) {
					c.add(t/i);
				}
				
				c.add((long)i);
			}
		}
		Collections.sort(c);
		Collections.reverse(c);
		return c;
	}
	
	
	private static long modPow(int i,int t,long mod) {
		//iのt乗をO(log t)で返す
		long a=i;
		long res=1;
		while(t!=0) {
			//p(t);
			if((1&t)==1) {
				res=res*a%mod;
			}
			a=a*a%mod;
			t=t>>1;
		}
		return res;
	}

	public static long gcd(long num1,long num2) {
        if(num2==0) return num1;
        else return gcd(num2,num1%num2);
    }
	public static long lcm(long num1,long num2) {
		return num1*num2/gcd(num1,num2);
	}
	//O(N^0.5)
	private static boolean isPrime(long t) {
		if(t<2)return false;
		for(int i=2;i*i<=t;i++) {
			if(t%i==0)return false;
		}
		return true;
	}
	private static ArrayList<Long> divisors(long t) {
		ArrayList<Long> c=new ArrayList<>();
		for(int i=1;i*i<=t;i++) {
			if(t%i==0) {
				if(i*i!=t) {
					c.add(t/i);
				}
				c.add((long)i);
			}
		}
		return c;
	}
	private static void bubunwa() {
		int N=sc.nextInt();
		int K=sc.nextInt();
		int a[]=sc.nextIntArray(N, false);

		boolean dp[] =new boolean[K+1];

		Arrays.fill(dp, false);
		dp[0]=true;
		for(int i=0;i<N;i++) {
			for(int x=K-a[i];x>=0;x--) {
				if(dp[x])dp[x+a[i]]=true;
			}
		}

		p(dp[K] ? "Yes":"No");
	}
	
	private static String bitToString(int i) {
		
			String T="";
			for(int j=0;j<2;j++) {
				//if(i>>j==0)break;
				if((1&i>>j)==1) {
					T+="1";
				}else T+="0";
			}
			return (i+" "+T);

		

	}
/*********************************************************************/
	//target以下までの値のindexを返す
	//target以上が欲しいときは返り値+1すればいい
	//0-indexで個数を求めるときはさらにindex+1する必要あり
	private static int lower_bound(long a[],long target) {
	//p(target+ " "+Arrays.toString(a));
	if(a[0]>target)return -1;
	//最後の値がtarget以下であるときは最後のindexを返す。
	//target以上が欲しいときは注意する必要あり
	if(a[a.length-1]<=target) return a.length-1;

	int S=-1;
	int E=a.length;

	while(S<E) {

		int G=(S+E)/2;
		if(G+1==a.length) {
			G--;
		}
		//未満にしたいときは=の場所を変える
		if(a[G]<=target&&a[G+1]>target) {
			return G;

		}else if(a[G]<=target){
			S=G;
		}else if(a[G]>target) {
			E=G;
		}

	}


	return -1;
	}
	static String nextPermutation(String s) {
		ArrayList<Character> list=new ArrayList<>();
		for(int i=0;i<s.length();i++) {
			list.add(s.charAt(i));
		}
		int pivotPos=-1;
		char pivot=0;
		for(int i=list.size()-2;i>=0;i--) {
			if(list.get(i)<list.get(i+1)) {
				pivotPos=i;
				pivot=list.get(i);
				break;
			}
		}
		if(pivotPos==-1&&pivot==0) {
			return "Final";
		}
		int L=pivotPos+1,R=list.size()-1;



		int minPos=-1;
		char min =Character.MAX_VALUE;

		for(int i=R;i>=L;i--) {
			if(pivot<list.get(i)) {
				if(list.get(i)<min) {
					min=list.get(i);
					minPos=i;
				}
			}
		}

		Collections.swap(list, pivotPos, minPos);
		Collections.sort(list.subList(L, R+1));


		StringBuilder sb=new StringBuilder();
		for(int i=0;i<list.size();i++) {
			sb.append(list.get(i));
		}
		return sb.toString();
	}
private static long[][] com;
private static void nCr() {
	int MAX = 3001;
	com= new long[MAX][MAX];
	for(int i = 0; i < MAX; i++)
	    com[i][0] = 1;
	for(int i = 1; i < MAX; i++) {
	    for(int j = 1; j <= i; j++) {
	        com[i][j] = com[i-1][j-1] + com[i-1][j];
	        com[i][j] %= mod;
	    }
	}
}


	static void p(String ans) {out.println(ans);};
	static void p(int ans) {out.println(ans);};
	static void p() {out.println();};
	static void p(long ans) {out.println(ans);};
	static void p(double ans) {out.println(ans);};

	static void pn(String ans) {out.print(ans);};
	static void pn(int ans) {out.print(ans);};
	static void pn() {out.print("");};
	static void pn(long ans) {out.print(ans);};
	static void pn(double ans) {out.print(ans);};

	static class FastScanner {
	    private final InputStream in = System.in;
	    private final byte[] buffer = new byte[1024];
	    private int ptr = 0;
	    private int buflen = 0;

	    private boolean hasNextByte() {
	      if (ptr < buflen) {
	        return true;
	      } else {
	        ptr = 0;
	        try {
	          buflen = in.read(buffer);
	        } catch (IOException e) {
	          e.printStackTrace();
	        }
	        if (buflen <= 0) {
	          return false;
	        }
	      }
	      return true;
	    }

	    private int readByte() {
	      if (hasNextByte()) return buffer[ptr++];
	      else return -1;
	    }

	    private static boolean isPrintableChar(int c) {
	      return 33 <= c && c <= 126;
	    }

	    private void skipUnprintable() {
	      while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
	    }

	    public boolean hasNext() {
	      skipUnprintable();
	      return hasNextByte();
	    }

	    public String next() {
	      if (!hasNext()) throw new NoSuchElementException();
	      StringBuilder sb = new StringBuilder();
	      int b = readByte();
	      while (isPrintableChar(b)) {
	        sb.appendCodePoint(b);
	        b = readByte();
	      }
	      return sb.toString();
	    }

	    public long nextLong() {
	      if (!hasNext()) throw new NoSuchElementException();
	      long n = 0;
	      boolean minus = false;
	      int b = readByte();
	      if (b == '-') {
	        minus = true;
	        b = readByte();
	      }
	      if (b < '0' || '9' < b) {
	        throw new NumberFormatException();
	      }
	      while (true) {
	        if ('0' <= b && b <= '9') {
	          n *= 10;
	          n += b - '0';
	        } else if (b == -1 || !isPrintableChar(b)) {
	          return minus ? -n : n;
	        } else {
	          throw new NumberFormatException();
	        }
	        b = readByte();
	      }
	    }

	    public int nextInt() {
	      return (int) nextLong();
	    }

	    public double nextDouble(){
	    	return Double.parseDouble(next());
	    }

	    public int[] nextIntArray(int N, boolean oneBased) {
	      if (oneBased) {
	        int[] array = new int[N + 1];
	        for (int i = 1; i <= N; i++) {
	          array[i] = sc.nextInt();
	        }
	        return array;
	      } else {
	        int[] array = new int[N];
	        for (int i = 0; i < N; i++) {
	          array[i] = sc.nextInt();
	        }
	        return array;
	      }
	    }

	    public long[] nextLongArray(int N, boolean oneBased) {
	      if (oneBased) {
	        long[] array = new long[N + 1];
	        for (int i = 1; i <= N; i++) {
	          array[i] = sc.nextLong();
	        }
	        return array;
	      } else {
	        long[] array = new long[N];
	        for (int i = 0; i < N; i++) {
	          array[i] = sc.nextLong();
	        }
	        return array;
	      }
	    }
	  }
}