n=int(input())

b=list(map(int,input().split()))

b.sort()
for i in range(n-1):
  if b[i]==b[i+1]:
    print("NO")
    break
  if i==n-2:
    print("YES") n=int(input()) n int(input()) int input() input b=list(map(int,input().split())) b list(map(int,input().split())) list map(int,input().split()) map int input().split() ().split () input split b.sort() b.sort b sort for i in range(n-1):
  if b[i]==b[i+1]:
    print("NO")
    break
  if i==n-2:
    print("YES") i range(n-1) range n-1 n 1 if b[i]==b[i+1]:
    print("NO")
    break
   b[i]==b[i+1] b[i] b i b[i+1] b i+1 i 1 print("NO") print "NO" break if i==n-2:
    print("YES") i==n-2 i n-2 n 2 print("YES") print "YES" b=list(map(int,input().split())) list(map(int,input().split())) b n=int(input()) int(input()) n
n=int(input())

b=list(map(int,input().split()))

b.sort()
for i in range(n-1):
  if b[i]==b[i+1]:
    print("NO")
    break
  if i==n-2:
    print("YES")