N = int(input())
A = list(map(int, input().split()))

flag = True
A = sorted(A)
for i in range(N-1):
  if A[i] == A[i+1]:
    flag = False
if flag:
  print("YES")
else:
  print("NO") 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 flag = True flag True A = sorted(A) A sorted(A) sorted A for i in range(N-1):
  if A[i] == A[i+1]:
    flag = False i range(N-1) range N-1 N 1 if A[i] == A[i+1]:
    flag = False A[i] == A[i+1] A[i] A i A[i+1] A i+1 i 1 flag = False flag False if flag:
  print("YES")
else:
  print("NO") flag print("YES") print "YES" print("NO") print "NO" A = sorted(A) sorted(A) A N = int(input()) int(input()) N A = list(map(int, input().split())) list(map(int, input().split())) A flag = True True flag flag = False False flag
N = int(input())
A = list(map(int, input().split()))

flag = True
A = sorted(A)
for i in range(N-1):
  if A[i] == A[i+1]:
    flag = False
if flag:
  print("YES")
else:
  print("NO")