#include <algorithm>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
//#include <regex>

/* g++ -g -std=c++0x */
/* g++ -g -std=c++11 */

using namespace std;

// std::ios::sync_with_stdio(false);

// freopen("input.txt", "rt", stdin);
// freopen("output.txt", "wt", stdout);

#define ALL(c)          (c).begin(), (c).end()
#define ALLR(c)         (c).rbegin(), (c).rend()
#define FOR(i,a,b)      for (int i=(a); i < (b); ++i)
#define FORR(i,a,b)     for (int i=(a); i > (b); --i)
#define FOR_ALL(i,c)    for (__typeof((c).begin()) i=(c).begin();   \
                             i != (c).end(); ++i)
#define FOR_ALLR(i,c)   for (__typeof((c).rbegin()) i=(c).rbegin(); \
                             i != (c).rend(); ++i)
#define SZ(array)       (sizeof(array)/sizeof(array[0]))
#define lc(x)           (x<<1)     /* 2*x */
#define rc(x)           (x<<1 | 1) /* 2*x+1 */
#define lowbit(x)       (x & (-x)) /* 0b10100 -> 0b100 */

typedef long long       LL;
typedef map<int,int>    MII;
typedef pair<int,int>   PII;
typedef set<int>        SI;
typedef vector<bool>    VB;
typedef vector<double>  VD;
typedef vector<int>     VI;
typedef vector<string>  VS;

/* check if a key is in container C */
template <class C>
inline bool in_(const typename C::key_type& k, const C& A)
{ return A.find(k) != A.end(); }
inline bool in_(const string& s, const string& S)
{ return S.find(s) != string::npos; }

/* Use min number of adj swap to make a derangement. */

const int inf = 1e9;
const int maxn = 1e5+5;
int dp[maxn][2];
int A[maxn], vis[maxn], color[maxn], cost[maxn];
VI V;

int find_cost(const int i, const int iscovered)
{
    if (i == 0)
        return !iscovered;      /* 1 swap if not covered */
    int& ans = dp[i][iscovered];
    if (ans == -1) {
        const int u = V[i];
        ans = cost[u] + find_cost(i-1, true);
        /* make a single swap w/ adj element */
        const int res = 1 + find_cost(i-1, V[i-1] == u-1);
        ans = min(ans,res);
        if (iscovered) {
            const int res = find_cost(i-1, false);
            ans = min(ans,res);
        }
    }
    return ans;
}

void dfs(const int u, const int c)
{
    vis[u] = true; color[u] = c;
    const int v = A[u];
    if (!vis[v])
        dfs(v,c);
}

int main()
{
/* #ifndef ONLINE_JUDGE */
/*     freopen("foo", "rt", stdin); */
/* #endif */
    int N;
    while (cin >> N) {
        FOR(i,1,N+1)
            cin >> A[i];
        memset(vis,0,sizeof(vis));
        FOR(i,1,N+1) if (!vis[i])
            dfs(i,i);           /* find cycle */
        map<int,int> comp;
        FOR(i,1,N+1)
            comp[color[i]]++;
        int pre = -1;
        V.clear();
        FOR_ALL(c,comp) if (c->second == 1) {
            const int u = c->first;
            if (pre != -1)
                cost[u] = u - pre;
            V.push_back(u);
            pre = u;
        }
        /* we want to find min cost to cover all nodes */
        memset(dp,-1,sizeof(dp));
        const int ans = find_cost(V.size()-1,false);
        cout << ans << endl;
    }
    return 0;
}


Measured memory_bytes: 14072