from collections import Counter
N=int(input())
A=list(map(int, input().split()))

cnt=Counter(A)
print("YES" if all([i==1 for i in cnt.values()]) else "NO") from collections import Counter 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 cnt=Counter(A) cnt Counter(A) Counter A i==1 for i in cnt.values() for i in cnt.values() i cnt.values() cnt.values cnt values for i in cnt.values() i==1 i 1 print("YES" if all([i==1 for i in cnt.values()]) else "NO") print "YES" if all([i==1 for i in cnt.values()]) else "NO" all([i==1 for i in cnt.values()]) all [i==1 for i in cnt.values()] "YES" "NO" A=list(map(int, input().split())) list(map(int, input().split())) A cnt=Counter(A) Counter(A) cnt N=int(input()) int(input()) N
from collections import Counter
N=int(input())
A=list(map(int, input().split()))

cnt=Counter(A)
print("YES" if all([i==1 for i in cnt.values()]) else "NO")