N=int(input())
A=list(map(int, input().split()))
A.sort()
if N==1:
  print('YES')
  exit()
for i in range(N-1):
  if A[i]==A[i+1]:
    print('NO')
    exit()
else:
  print('YES') 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 if N==1:
  print('YES')
  exit() N==1 N 1 print('YES') print 'YES' exit() exit for i in range(N-1):
  if A[i]==A[i+1]:
    print('NO')
    exit()
else:
  print('YES') i range(N-1) range N-1 N 1 if A[i]==A[i+1]:
    print('NO')
    exit() A[i]==A[i+1] A[i] A i A[i+1] A i+1 i 1 print('NO') print 'NO' exit() exit print('YES') print 'YES' N=int(input()) int(input()) N A=list(map(int, input().split())) list(map(int, input().split())) A
N=int(input())
A=list(map(int, input().split()))
A.sort()
if N==1:
  print('YES')
  exit()
for i in range(N-1):
  if A[i]==A[i+1]:
    print('NO')
    exit()
else:
  print('YES')