#include <cstdio>

int N, A[51];
bool used[51];

int main(){
    scanf("%d", &N);

    for(int i=1;i<=N;i++){
        scanf("%d", A+i);
    }

    int n2 = 0;
    for(int i=1;i<=N;i++){
        if(used[i]){continue;}

        int t = 1;
        for(int j=A[i];j!=i;j=A[j]){used[j] = true; t++;}

        if(t == 2){n2++;}
    }
    if(n2 & 1){puts("No");}
    else{puts("Yes");}
}