N = int(input())
A = list(map(int, input().split()))
A.sort()
a = A[0]
for i in A[1:]:
    if i - a == 0:
        print("NO")
        break
    else:
        a = i
else:
    print("YES")
 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 a = A[0] a A[0] A 0 for i in A[1:]:
    if i - a == 0:
        print("NO")
        break
    else:
        a = i
else:
    print("YES") i A[1:] A 1: 1 if i - a == 0:
        print("NO")
        break
    else:
        a = i i - a == 0 i - a i a 0 print("NO") print "NO" break a = i a i print("YES") print "YES" A = list(map(int, input().split())) list(map(int, input().split())) A a = i i a N = int(input()) int(input()) N a = A[0] A[0] a
N = int(input())
A = list(map(int, input().split()))
A.sort()
a = A[0]
for i in A[1:]:
    if i - a == 0:
        print("NO")
        break
    else:
        a = i
else:
    print("YES")

