//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2")
 
#include <bits/stdc++.h>
#include <vector>
#include <set>
#include <map>
#include <string> 
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <utility>
#include <algorithm>
#include <cmath>
#include <queue>
#include <stack>
#include <iomanip> 
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp> 
//setbase - cout << setbase (16)a; cout << 100 << endl; Prints 64
//setfill -   cout << setfill ('x') << setw (5); cout << 77 <<endl;prints xxx77
//setprecision - cout << setprecision (14) << f << endl; Prints x.xxxx
//cout.precision(x)  cout<<fixed<<val;  // prints x digits after decimal in val

using namespace std;
using namespace __gnu_pbds;
#define pb push_back
#define mp make_pair
#define vi vector< int >
#define vl vector< ll >
#define ss second
#define ff first
#define ll long long
#define pii pair< int,int >
#define pll pair< ll,ll >
#define sz(a) a.size()
#define inf (1000*1000*1000+5)
#define all(a) a.begin(),a.end()
#define tri pair<int,pii>
#define vii vector<pii>
#define vll vector<pll>
#define viii vector<tri>
#define mod (1000*1000*1000+7)
#define pqueue priority_queue< int >
#define pdqueue priority_queue< int,vi ,greater< int > >
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define for0(i, n) for (int i = 0; i < (int)(n); ++i) // 0 based indexing
#define for1(i, n) for (int i = 1; i <= (int)(n); ++i) // 1 based indexing
#define forc(i, l, r) for (int i = (int)(l); i <= (int)(r); ++i) // closed interver from l to r r inclusive
#define forr0(i, n) for (int i = (int)(n) - 1; i >= 0; --i) // reverse 0 based.
#define forr1(i, n) for (int i = (int)(n); i >= 1; --i) // reverse 1 based
#define rall(x) (x).rbegin, (x).rend() //reverse traversal

 
typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;

int main(){
	fastio;
	int t;
	cin>>t;
	cout<<((t+100-1)/100)<<endl;
}
#include<bits/stdc++.h>
using namespace std;
#define FastIO ios_base::sync_with_stdio(false); cin.tie(0);
#define ll long long
#define ull unsigned long long
#define pb push_back
#define All(x) (x).begin(),(x).end()
#define mp make_pair
#define nl "\n"
typedef pair<int,int>ii;
typedef vector<int>vi;
typedef vector<ii>vii;
typedef vector<vi>vvi;
typedef vector<long long>vl;
typedef vector <vl>vvl;
template<class T>
void print(T& a)
{
    for(auto x:a)
        cout<<x<<" ";
    cout<<"\n";
}
const int MX=2e5+5;
int to[MX];

int findto(int x)
{
    if(to[x]==x)return x;
    else to[x]=findto(to[x]);
    return to[x];
}

int main()
{

    FastIO

    int n,ans=0; cin>>n;
    int a[n];
    for(int &x:a)cin>>x;

    iota(to,to+MX,0);

    for(int i=0; i<(n/2); i++)
    {
        int x=findto(a[i]);
        int y=findto(a[n-1-i]);
        if(x==y)continue;
        else
        {
            ans++;
            to[x]=y;
        }
    }

    cout<<ans<<nl;

    return 0;
}