N=int(raw_input())
a=map(int,raw_input().split())
loopCnt=[0 for i in range(N+1)]
for i in range(len(a)):
    if a[i]!=-1 and a[i]!=i+1:
        cnt=1
        cur=i
        while a[cur]!=i+1:
            cnt+=1
            tmp=cur
            cur=a[cur]-1
            a[tmp]=-1
        a[cur]=-1
        loopCnt[cnt]+=1 
for i in range(2,N+1,2):
    if loopCnt[i] %2 ==1:
        print "No"
        exit()
print "Yes"