n = int(input())
s = [int(i) for i in input().split()]
s.sort()
flag = False
for i in range (0,n-1):
  if s[i] == s[i+1]:
    flag = True
    break
if flag == True:
  print("NO")
else: print("YES") n = int(input()) n int(input()) int input() input int(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() int(i) int i s = [int(i) for i in input().split()] s [int(i) for i in input().split()] s.sort() s.sort s sort flag = False flag False for i in range (0,n-1):
  if s[i] == s[i+1]:
    flag = True
    break i range (0,n-1) range 0 n-1 n 1 if s[i] == s[i+1]:
    flag = True
    break s[i] == s[i+1] s[i] s i s[i+1] s i+1 i 1 flag = True flag True break if flag == True:
  print("NO")
else: print("YES") flag == True flag True print("NO") print "NO" s = [int(i) for i in input().split()] [int(i) for i in input().split()] s n = int(input()) int(input()) n flag = False False flag flag = True True flag
n = int(input())
s = [int(i) for i in input().split()]
s.sort()
flag = False
for i in range (0,n-1):
  if s[i] == s[i+1]:
    flag = True
    break
if flag == True:
  print("NO")
else: print("YES")