N=int(input())
#b,c=int(input()),int(input())
# c=[]
#  for i in b:
#     c.append(i)
#e1,e2 = map(int,input().split())
A = list(map(int,input().split()))
#j = [input() for _ in range(a)]
# h = []
# for i in range(e1):
#     h.append(list(map(int,input().split())))
A.sort()
ans="YES"
for i in range(1,N):
    if A[i-1]==A[i]:
        ans="NO"
        break
print(ans) 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 A.sort() A.sort A sort ans="YES" ans "YES" for i in range(1,N):
    if A[i-1]==A[i]:
        ans="NO"
        break i range(1,N) range 1 N if A[i-1]==A[i]:
        ans="NO"
        break A[i-1]==A[i] A[i-1] A i-1 i 1 A[i] A i ans="NO" ans "NO" break print(ans) print ans N=int(input()) int(input()) N ans="YES" "YES" ans ans="NO" "NO" ans A = list(map(int,input().split())) list(map(int,input().split())) A
N=int(input())
#b,c=int(input()),int(input())
# c=[]
#  for i in b:
#     c.append(i)
#e1,e2 = map(int,input().split())
A = list(map(int,input().split()))
#j = [input() for _ in range(a)]
# h = []
# for i in range(e1):
#     h.append(list(map(int,input().split())))
A.sort()
ans="YES"
for i in range(1,N):
    if A[i-1]==A[i]:
        ans="NO"
        break
print(ans)