#include <bits/stdc++.h>
using namespace std;

int n;
vector<int> s;
vector<int> state;   // 0 = nem látogatot, 1 = látogatjuk, 2 = megvan


void dfs(int u, int &cycles) {
    state[u] = 1;
    int v = s[u];

    if (state[v] == 0) {
        dfs(v, cycles);
    } else if (state[v] == 1) {
        cycles++;
    }

    state[u] = 2;
}

int count_cycles() {
    int cycles = 0;
    for (int i = 1; i <= n; i++) {
        if (state[i] == 0) {
            dfs(i, cycles);
        }
    }
    return cycles;
}


void print_seating() {
    for (int i = 1; i <= n; i++) {
        cout << i << " ";
    }
    cout << "\n";
}


int main() {
    cin >> n;
    s.resize(n + 1);
    state.assign(n + 1, 0);

    for (int i = 1; i <= n; i++) {
        cin >> s[i];
    }

    int cycles = count_cycles();
    int M = n - cycles;

    cout << M << "\n";
    print_seating();
}