from collections import Counter
N = int(input())
A = list(map(int, input().split()))
cnt = Counter(A)
print('YES' if len(cnt) == N else 'NO') from collections import Counter N = int(input()) N int(input()) int input() input A = list(map(int, input().split())) A list(map(int, input().split())) list map(int, input().split()) map int input().split() ().split () input split cnt = Counter(A) cnt Counter(A) Counter A print('YES' if len(cnt) == N else 'NO') print 'YES' if len(cnt) == N else 'NO' len(cnt) == N len(cnt) len cnt N 'YES' 'NO' A = list(map(int, input().split())) list(map(int, input().split())) A cnt = Counter(A) Counter(A) cnt N = int(input()) int(input()) N
from collections import Counter
N = int(input())
A = list(map(int, input().split()))
cnt = Counter(A)
print('YES' if len(cnt) == N else 'NO')
