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 int MOD = 1e9 + 7;
int a[200001];
int visited[200001];
vector<long long> fixedpt;
vector<long long> repair;
bool empt;
void dfs(int u) {
  visited[u] = 2;
  int v = a[u];
  if (v == u) {
  } else if (visited[v] == 2) {
    repair.push_back(v);
  } else if (visited[v] == 1) {
  } else {
    dfs(v);
  }
  visited[u] = 1;
}
int main() {
  int n;
  int cnt = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    a[i]--;
    if (a[i] == i) fixedpt.push_back(i);
  }
  empt = false;
  if (fixedpt.empty()) empt = true;
  if (!fixedpt.empty()) {
    for (int i = 0; i < fixedpt.size(); i++) {
      a[fixedpt[i]] = fixedpt[0];
      if (i > 0) cnt++;
    }
  }
  for (int i = 0; i < n; i++) {
    if (!visited[i]) dfs(i);
  }
  for (int i = 0; i < repair.size(); i++) {
    if (fixedpt.empty()) {
      a[repair[i]] = repair[0];
    } else {
      a[repair[i]] = fixedpt[0];
    }
    cnt++;
  }
  printf("%d\n", cnt);
  for (int i = 0; i < n; i++) {
    printf("%d ", a[i] + 1);
  }
}
