n = int(input())
a = list(map(int,input().split()))
b = sorted(a)
memo = 0
for i in range(n-1):
  if(b[i]==b[i+1]):
    memo +=1
if(memo==0):
  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 b = sorted(a) b sorted(a) sorted a memo = 0 memo 0 for i in range(n-1):
  if(b[i]==b[i+1]):
    memo +=1 i range(n-1) range n-1 n 1 if(b[i]==b[i+1]):
    memo +=1 b[i]==b[i+1] b[i] b i b[i+1] b i+1 i 1 memo +=1 memo 1 if(memo==0):
  print("YES")
else:
  print("NO") memo==0 memo 0 print("YES") print "YES" print("NO") print "NO" memo +=1 1 memo a = list(map(int,input().split())) list(map(int,input().split())) a memo = 0 0 memo b = sorted(a) sorted(a) b n = int(input()) int(input()) n
n = int(input())
a = list(map(int,input().split()))
b = sorted(a)
memo = 0
for i in range(n-1):
  if(b[i]==b[i+1]):
    memo +=1
if(memo==0):
  print("YES")
else:
  print("NO")