3
2 1 1
 6
6 2 6 2 4 2
 2
1 2
 8
2 1 2 2 6 5 6 6
 18
2 3 4 5 2 7 8 9 10 7 11 12 14 15 13 17 18 18
 7
1 2 3 4 5 6 7
 7
4 3 2 6 3 5 2
 7
7 5 3 1 2 1 5
 7
1 6 4 4 5 6 7

1
2 2 1  0
6 2 6 2 4 2  1 
1 1 
 2 
2 2 2 2 6 2 6 6 
 5 
2 3 4 5 11 7 8 9 10 11 11 11 14 15 11 17 18 11 
 6 
1 1 1 1 1 1 1 
 1
4 3 3 6 3 5 2  1
7 5 3 1 3 1 5  4 
1 6 4 1 1 1 1 

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Random;
import java.util.StringTokenizer;
import java.util.TreeSet;

public class cf {

	public static void main(String[] args) throws IOException {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = sc.nextIntArray(n);
		int r = -1;
		DSU uf = new DSU(n);
		int count = 0;
		for (int i = 0; i < n; i++) {
			if (p[i] == i + 1) {
				if (r == -1)
					r = i + 1;
				else {
					p[i] = r;
					count++;
				}
			}
			if (i == n - 1 && r == -1) {
				r = p[i];
				p[r - 1] = r;
				count++;
			}

		}

		for (int i = 0; i < n; i++)
			if (!uf.union(i, p[i] - 1)) {
				p[i] = r;
				uf.union(i, p[i] - 1);
				count++;
			}

		PrintWriter out = new PrintWriter(System.out);
		out.println(count - 1);
		for (int i = 0; i < n; i++)
			out.print(p[i] + " ");
		out.close();

	}

	static class DSU {
		int[] p;
		int[] r;

		public DSU(int n) {
			p = new int[n];
			r = new int[n];
			for (int i = 0; i < n; i++)
				p[i] = i;
		}

		public boolean isSameSet(int x, int y) {
			return findSet(x) == findSet(y);
		}

		public int findSet(int x) {
			return x == p[x] ? x : (p[x] = findSet(p[x]));
		}

		public boolean union(int x, int y) {
			x = findSet(x);
			y = findSet(y);
			if (x == y)
				return false;
			if (r[x] > r[y])
				p[y] = x;
			else {
				p[x] = y;
				if (r[x] == r[y]) {
					r[y]++;
				}
			}
			return true;
		}
	}

	static class Scanner {
		StringTokenizer st;
		BufferedReader br;

		public Scanner(InputStream s) {
			br = new BufferedReader(new InputStreamReader(s));
		}

		public Scanner(String f) throws FileNotFoundException {
			br = new BufferedReader(new FileReader(f));
		}

		public String next() throws IOException {
			while (st == null || !st.hasMoreTokens())
				st = new StringTokenizer(br.readLine());
			return st.nextToken();
		}

		public int nextInt() throws IOException {
			return Integer.parseInt(next());
		}

		public long nextLong() throws IOException {
			return Long.parseLong(next());
		}

		public String nextLine() throws IOException {
			return br.readLine();
		}

		public double nextDouble() throws IOException {
			return Double.parseDouble(next());
		}

		public boolean ready() throws IOException {
			return br.ready();
		}

		public int[] nextIntArray(int n) throws IOException {
			int[] a = new int[n];
			for (int i = 0; i < n; i++)
				a[i] = nextInt();
			return a;
		}

		public int[] nextIntArray1(int n) throws IOException {
			int[] a = new int[n + 1];
			for (int i = 1; i <= n; i++)
				a[i] = nextInt();
			return a;
		}

		public int[] shuffle(int[] a, int n) {
			int[] b = new int[n];
			for (int i = 0; i < n; i++)
				b[i] = a[i];
			Random r = new Random();
			for (int i = 0; i < n; i++) {
				int j = i + r.nextInt(n - i);
				int t = b[i];
				b[i] = b[j];
				b[j] = t;
			}
			return b;
		}

		public int[] nextIntArraySorted(int n) throws IOException {
			int[] a = nextIntArray(n);
			a = shuffle(a, n);
			Arrays.sort(a);
			return a;
		}

		public long[] nextLongArray(int n) throws IOException {
			long[] a = new long[n];
			for (int i = 0; i < n; i++)
				a[i] = nextLong();
			return a;
		}

		public long[] nextLongArray1(int n) throws IOException {
			long[] a = new long[n + 1];
			for (int i = 1; i <= n; i++)
				a[i] = nextLong();
			return a;
		}

		public long[] nextLongArraySorted(int n) throws IOException {
			long[] a = nextLongArray(n);
			Random r = new Random();
			for (int i = 0; i < n; i++) {
				int j = i + r.nextInt(n - i);
				long t = a[i];
				a[i] = a[j];
				a[j] = t;
			}
			Arrays.sort(a);
			return a;
		}
	}

}
