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