n = int(input())
a = list(map(int, input().split()))
a = sorted(a)
ans = "YES"

for i in range(n-1):
    if a[i] == a[i+1]:
        ans = "NO"
        break

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

for i in range(n-1):
    if a[i] == a[i+1]:
        ans = "NO"
        break

print(ans)
