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>
#pragma warning(disable : 4996)
using namespace std;
using ld = long double;
template <class T>
using Table = vector<vector<T>>;
const ld eps = 1e-9;
struct Dscc {
 public:
  pair<vector<vector<int>>, vector<vector<int>>> get(
      const vector<vector<int>> &edges) {
    nums.resize(edges.size());
    fill(nums.begin(), nums.end(), -1);
    vector<vector<int>> revedges(edges.size());
    for (int i = 0; i < edges.size(); ++i) {
      for (auto j : edges[i]) {
        revedges[j].push_back(i);
      }
    }
    int num = 0;
    for (int i = 0; i < edges.size(); ++i) {
      dfs(i, num, edges);
    }
    vector<int> big(nums.size());
    for (int i = 0; i < nums.size(); ++i) {
      big[nums[i]] = i;
    }
    reverse(big.begin(), big.end());
    unis.resize(edges.size());
    fill(unis.begin(), unis.end(), -1);
    num = 0;
    for (int i = 0; i < big.size(); ++i) {
      dfs2(big[i], num, revedges);
      num++;
    }
    vector<int> nums;
    for (int i = 0; i < unis.size(); ++i) {
      nums.push_back(unis[i]);
    }
    sort(nums.begin(), nums.end());
    nums.erase(unique(nums.begin(), nums.end()), nums.end());
    map<int, int> mp;
    for (int i = 0; i < nums.size(); ++i) {
      mp[nums[i]] = i;
    }
    for (int i = 0; i < unis.size(); ++i) {
      unis[i] = mp[unis[i]];
    }
    vector<vector<int>> belongs(nums.size());
    for (int i = 0; i < unis.size(); ++i) {
      belongs[unis[i]].push_back(i);
    }
    vector<vector<int>> newedges(nums.size());
    for (int i = 0; i < edges.size(); ++i) {
      for (auto j : edges[i]) {
        if (unis[i] != unis[j]) {
          newedges[unis[i]].push_back(unis[j]);
        }
      }
    }
    return make_pair(belongs, newedges);
  }

 private:
  vector<int> nums;
  vector<int> unis;
  void dfs(const int id, int &num, const vector<vector<int>> &edges) {
    if (nums[id] != -1)
      return;
    else {
      nums[id] = -2;
      for (auto i : edges[id]) {
        dfs(i, num, edges);
      }
    }
    nums[id] = num++;
    return;
  }
  void dfs2(const int id, const int &num, const vector<vector<int>> &edges) {
    if (unis[id] != -1)
      return;
    else {
      unis[id] = -2;
      for (auto i : edges[id]) dfs2(i, num, edges);
    }
    unis[id] = num;
    return;
  }
} dscc;
int main() {
  int N;
  cin >> N;
  vector<int> as(N);
  for (int i = 0; i < N; ++i) {
    cin >> as[i];
    as[i]--;
  }
  vector<int> selfs;
  for (int i = 0; i < N; ++i) {
    selfs.push_back(as[i] == i);
  }
  int ans = 0;
  int pa;
  if (accumulate(selfs.begin(), selfs.end(), 0) == 0) {
    bool flag = false;
    vector<vector<int>> edges(N);
    for (int i = 0; i < N; ++i) {
      edges[i].push_back(as[i]);
    }
    auto p = dscc.get(edges);
    for (int i = 0; i < p.first.size(); ++i) {
      if (p.second[i].empty()) {
        if (!flag) {
          pa = p.first[i][0];
          as[pa] = pa;
          ans++;
          flag = true;
        } else {
          as[p.first[i][0]] = pa;
          ans++;
        }
      }
    }
  } else {
    bool flag = false;
    for (int i = 0; i < N; ++i) {
      if (!flag) {
        if (as[i] == i) {
          pa = i;
          flag = true;
        }
      } else {
        if (as[i] == i) {
          as[i] = pa;
          ans++;
        }
      }
    }
    vector<vector<int>> edges(N);
    for (int i = 0; i < N; ++i) {
      edges[i].push_back(as[i]);
    }
    auto p = dscc.get(edges);
    for (int i = 0; i < p.first.size(); ++i) {
      if (p.second[i].empty()) {
        if (!flag) {
          pa = p.first[i][0];
          as[pa] = pa;
          ans++;
          flag = true;
        } else {
          if (as[p.first[i][0]] != pa) {
            as[p.first[i][0]] = pa;
            ans++;
          }
        }
      }
    }
  }
  cout << ans << endl;
  for (int i = 0; i < as.size(); ++i) {
    cout << as[i] + 1;
    if (i == as.size() - 1)
      cout << endl;
    else
      cout << " ";
  }
  return 0;
}
