#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=1167167167167167167;
const int INF=100000000;
const ll mod=1e9+7;
#define rep(i,a) for (ll i=0;i<a;i++)
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}


namespace po167{
//LCP vec[0,n) and vec[i,n)
//for all i 
//O(vec.size())
template<class T>
std::vector<int> Z_algo(std::vector<T> &vec){
	int n=vec.size();
	int ind=1,j=0,k;
	std::vector<int> ans(n,0);
	ans[0]=n;
	while(ind<n){
		while(ind+j<n&&vec[j]==vec[ind+j]) j++;
		ans[ind]=j;
		if(j==0){
			ind++;
			continue;
		}
		k=1;
		while(k+ind<n&&ans[k]+k<j){
			ans[k+ind]=ans[k];
			k++;
		}
		j-=k;
		ind+=k;
	}
	return ans;
}
std::vector<int> Z_algo(std::string &vec){
	int n=vec.size();
	int ind=1,j=0,k;
	std::vector<int> ans(n,0);
	ans[0]=n;
	while(ind<n){
		while(ind+j<n&&vec[j]==vec[ind+j]) j++;
		ans[ind]=j;
		if(j==0){
			ind++;
			continue;
		}
		k=1;
		while(k+ind<n&&ans[k]+k<j){
			ans[k+ind]=ans[k];
			k++;
		}
		j-=k;
		ind+=k;
	}
	return ans;
}
}
using po167::Z_algo;

void solve();

//  rainy ~ 雨に打たれて ~
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int t=1;
	//cin>>t;
	rep(i,t) solve();
}

void solve(){
	int N;
	cin>>N;
	vector<int> p(N);
	rep(i,N){
		cin>>p[i];
	}
	auto q=p;
	So(q);
	for(int i=N-1;i>=0;i--){
		if(p[i]!=q[i]){
			int s=i+1;
			vector<int> r(s*3+1);
			rep(j,s){
				r[j]=p[j];
				r[j+s+1]=q[j];
				r[j+s*2+1]=q[j];
			}
			r[s]=-1;
			auto Z=Z_algo(r);
			rep(j,3*s){
				if(Z[j+1]==s){
					cout<<"1\n";
					return;
				}
			}
			cout<<"2\n";
			return;
		}
	}
	cout<<"0\n";
}