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