import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		HashMap<String, Integer> map = new HashMap<String, Integer>();
		
		for(int i = 0; i < N; i++){
			final String input = sc.next();
			
			if(!map.containsKey(input)){
				map.put(input, 0);
			}
			map.put(input, map.get(input) + 1);
		}
		
		int[] array = new int[map.size()];
		{
			int count = 0;
			for(final int value : map.values()){
				array[count++] = value;
			}
		}
		Arrays.sort(array);
		
		//System.out.println(Arrays.toString(array));
		
		if(array.length == 1 && array[0] >= 2){
			System.out.println("NO");
			return;
		}else if(array.length == 2){
			if((array[0] - 1) > array[1]){
				System.out.println("NO");
				return;
			}else if((array[0] + 1) < array[1]){
				System.out.println("NO");
				return;
			}
		}
		
		int ok_count = array[0] + array[1];
		for(int i = 2; i < array.length; i++){
			if(ok_count + 1 < array[i]){
				System.out.println("NO");
				return;
			}
			
			ok_count += array[i];
		}
		
		System.out.println("YES");
		
	}

}