import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
 

//result = Math.pow(num1, num3)
//StringBuffer str = new StringBuffer(hoge1);
//String hoge2 = str.reverse().toString();
public class Main {
	private static Scanner sc = new Scanner(System.in);
	static void p(String ans) {System.out.println(ans);};
	static void p(int ans) {System.out.println(ans);};
	static void p(long ans) {System.out.println(ans);};
	//static String eikomoji[]={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
	
	
	public static void main(String[] args) {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 }
} import java.util.ArrayList; ArrayList java.util import java.util.Collection; Collection java.util import java.util.Collections; Collections java.util import java.util.Comparator; Comparator java.util import java.util.HashMap; HashMap java.util import java.util.List; List java.util import java.util.Map; Map java.util import java.util.Map.Entry; Entry java.util.Map import java.util.Scanner; Scanner java.util public class Main {
	private static Scanner sc = new Scanner(System.in);
	static void p(String ans) {System.out.println(ans);};
	static void p(int ans) {System.out.println(ans);};
	static void p(long ans) {System.out.println(ans);};
	//static String eikomoji[]={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
	
	
	public static void main(String[] args) {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 }
} Main private static Scanner sc = new Scanner(System.in); sc new Scanner(System.in) static void p(String ans) {System.out.println(ans);} p {System.out.println(ans);} System.out.println(ans) System.out.println System.out System System.out ans String ans ans static void p(int ans) {System.out.println(ans);} p {System.out.println(ans);} System.out.println(ans) System.out.println System.out System System.out ans int ans ans static void p(long ans) {System.out.println(ans);} p {System.out.println(ans);} System.out.println(ans) System.out.println System.out System System.out ans long ans ans public static void main(String[] args) {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 } main {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 } int n=sc.nextInt(); n sc.nextInt() sc.nextInt sc Map<Integer, Integer> map = new HashMap<Integer, Integer>(n); map new HashMap<Integer, Integer>(n) boolean a=true; a true for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	} int i=0; int i=0; i 0 i<n&&a i<n i n a i++ i++ i {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	} {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	} int A = sc.nextInt(); A sc.nextInt() sc.nextInt sc if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		} !map.containsKey(A) map.containsKey(A) map.containsKey map A {
			map.put(A,1);
		} map.put(A,1) map.put map A 1 {
			a=false;
			
		} a=false a false if(a) {
		p("YES");
	}else {
		p("NO");
	} a {
		p("YES");
	} p("YES") p "YES" {
		p("NO");
	} p("NO") p "NO" String[] args args public class Main {
	private static Scanner sc = new Scanner(System.in);
	static void p(String ans) {System.out.println(ans);};
	static void p(int ans) {System.out.println(ans);};
	static void p(long ans) {System.out.println(ans);};
	//static String eikomoji[]={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
	
	
	public static void main(String[] args) {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 }
} public class Main {
	private static Scanner sc = new Scanner(System.in);
	static void p(String ans) {System.out.println(ans);};
	static void p(int ans) {System.out.println(ans);};
	static void p(long ans) {System.out.println(ans);};
	//static String eikomoji[]={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
	
	
	public static void main(String[] args) {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 }
} Main
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Scanner;
 

//result = Math.pow(num1, num3)
//StringBuffer str = new StringBuffer(hoge1);
//String hoge2 = str.reverse().toString();
public class Main {
	private static Scanner sc = new Scanner(System.in);
	static void p(String ans) {System.out.println(ans);};
	static void p(int ans) {System.out.println(ans);};
	static void p(long ans) {System.out.println(ans);};
	//static String eikomoji[]={"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
	
	
	public static void main(String[] args) {
	int n=sc.nextInt();
	Map<Integer, Integer> map = new HashMap<Integer, Integer>(n);
	boolean a=true;
	for(int i=0;i<n&&a;i++) {
		int A = sc.nextInt();
		
		if(!map.containsKey(A)) {
			map.put(A,1);
		}else {
			a=false;
			
		}
	}
	//Map<String, Integer> map = new HashMap<String, Integer>(n);
	//ArrayList<String> cc = new ArrayList<>(n);
	if(a) {
		p("YES");
	}else {
		p("NO");
	}


	
	
	
	
 }
}