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