st = set()
n = int(input())
ls = [int(x) for x in input().split()]
for i in ls:
  st.add(i)
  
if len(st) == n:
  print("YES")
else:
  print("NO") st = set() st set() set n = int(input()) n int(input()) int input() input int(x) for x in input().split() for x in input().split() x input().split() ().split () input split for x in input().split() int(x) int x ls = [int(x) for x in input().split()] ls [int(x) for x in input().split()] for i in ls:
  st.add(i)
   i ls st.add(i) st.add st add i if len(st) == n:
  print("YES")
else:
  print("NO") len(st) == n len(st) len st n print("YES") print "YES" print("NO") print "NO" n = int(input()) int(input()) n ls = [int(x) for x in input().split()] [int(x) for x in input().split()] ls st = set() set() st
st = set()
n = int(input())
ls = [int(x) for x in input().split()]
for i in ls:
  st.add(i)
  
if len(st) == n:
  print("YES")
else:
  print("NO")