n = int(input())
*r, = map(int,input().split())
for i in range(n): r[i] -= 1

from collections import Counter
d = Counter()
used = [0]*n
for i in range(n):
    if used[i]: continue
    cnt = 0
    while used[i]==0:
        used[i] = 1
        i = r[i]
        cnt += 1
    d[cnt] += 1

print("No" if any(k%2==0 and v%2==1 for k,v in d.items()) else "Yes")