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 

#include <bits/stdc++.h>
using namespace std;
const long long mod = 1000000007;
const long long inf = mod * mod;
int p[210000];
int v[210000];
int main() {
  int a;
  scanf("%d", &a);
  for (int i = 0; i < a; i++) {
    scanf("%d", p + i);
    p[i]--;
  }
  int ret = 0;
  int par = -1;
  int sec = -1;
  for (int i = 0; i < a; i++) {
    if (v[i]) continue;
    int at = i;
    vector<int> vis;
    v[at] = 2;
    vis.push_back(at);
    while (1) {
      int to = p[at];
      if (v[to] == 1) break;
      if (v[to] == 2) {
        if (to != at) {
          ret++;
          p[at] = -1;
          sec = at;
        } else {
          if (!~par) {
            par = at;
          } else {
            ret++;
            p[at] = par;
          }
        }
        break;
      }
      v[to] = 2;
      at = to;
      vis.push_back(to);
    }
    for (int j = 0; j < vis.size(); j++) {
      v[vis[j]] = 1;
    }
  }
  for (int i = 0; i < a; i++) {
    if (p[i] == -1) {
      if (~par)
        p[i] = par;
      else
        p[i] = sec;
    }
  }
  printf("%d\n", ret);
  for (int i = 0; i < a; i++) {
    if (i) printf(" ");
    printf("%d", p[i] + 1);
  }
  printf("\n");
}
