N = int(input())
A = list(map(int, input().split()))
sort_A = sorted(A)
str_A = list(map(str, sort_A))
o = 'YES'
for i in range(1, len(A)):
	if str_A[i-1] == str_A[i]:
		o = 'NO'
		break
print(o) 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 sort_A = sorted(A) sort_A sorted(A) sorted A str_A = list(map(str, sort_A)) str_A list(map(str, sort_A)) list map(str, sort_A) map str sort_A o = 'YES' o 'YES' for i in range(1, len(A)):
	if str_A[i-1] == str_A[i]:
		o = 'NO'
		break i range(1, len(A)) range 1 len(A) len A if str_A[i-1] == str_A[i]:
		o = 'NO'
		break str_A[i-1] == str_A[i] str_A[i-1] str_A i-1 i 1 str_A[i] str_A i o = 'NO' o 'NO' break print(o) print o o = 'NO' 'NO' o A = list(map(int, input().split())) list(map(int, input().split())) A N = int(input()) int(input()) N sort_A = sorted(A) sorted(A) sort_A str_A = list(map(str, sort_A)) list(map(str, sort_A)) str_A o = 'YES' 'YES' o
N = int(input())
A = list(map(int, input().split()))
sort_A = sorted(A)
str_A = list(map(str, sort_A))
o = 'YES'
for i in range(1, len(A)):
	if str_A[i-1] == str_A[i]:
		o = 'NO'
		break
print(o)