#include <cassert>// c
#include <iostream>// io
#include <iomanip>
#include <fstream>
#include <sstream>
#include <vector>// container
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <algorithm>// other
#include <complex>
#include <numeric>
#include <functional>
#include <random>
#include <regex>
using namespace std;

typedef long long ll;typedef unsigned long long ull;typedef long double ld;

#define ALL(c) c.begin(),c.end()
#define IN(l,v,r) (l<=v && v < r)
template<class T> void UNIQUE(T v){v.erase(unique(ALL(v)),v.end());}
//debug
#define DUMP(x) cerr << #x <<" = " << (x)
#define LINE() cerr<< " (L" << __LINE__ << ")"

struct range{
    struct Iter{
        int v,step;
        Iter& operator++(){v+=step;return *this;}
        bool operator!=(Iter& itr){return v<itr.v;}
        int& operator*(){return v;}
    };
    Iter i, n;
    range(int i, int n,int step):i({i,step}), n({n,step}){}
    range(int i, int n):range(i,n,1){}
    range(int n):range(0,n){}
    Iter& begin(){return i;}
    Iter& end(){return n;}
};
struct rrange{
    struct Iter{
        int v,step;
        Iter& operator++(){v-=step;return *this;}
        bool operator!=(Iter& itr){return v>itr.v;}
        int& operator*(){return v;}
    };
    Iter i, n;
    rrange(int i, int n,int step):i({i-1,step}), n({n-1,step}){}
    rrange(int i, int n):rrange(i,n,1){}
    rrange(int n) :rrange(0,n){}
    Iter& begin(){return n;}
    Iter& end(){return i;}
};

//input
template<typename T1,typename T2> istream& operator >> (istream& is,pair<T1,T2>& p){return is>>p.first>>p.second;}
template<typename T1> istream& operator >> (istream& is,tuple<T1>& t){return is >> get<0>(t);}
template<typename T1,typename T2> istream& operator >> (istream& is,tuple<T1,T2>& t){return is >> get<0>(t) >> get<1>(t);}
template<typename T1,typename T2,typename T3> istream& operator >> (istream& is,tuple<T1,T2,T3>& t){return is >>get<0>(t)>>get<1>(t)>>get<2>(t);}
template<typename T1,typename T2,typename T3,typename T4> istream& operator >> (istream& is,tuple<T1,T2,T3,T4>& t){return is >> get<0>(t)>>get<1>(t)>>get<2>(t)>>get<3>(t);}
template<typename T> istream& operator >> (istream& is,vector<T>& as){for(int i:range(as.size()))is >>as[i];return is;}
//output
template<typename T> ostream& operator << (ostream& os, const set<T>& ss){for(auto a:ss){if(a!=ss.begin())os<<" "; os<<a;}return os;}
template<typename T1,typename T2> ostream& operator << (ostream& os, const pair<T1,T2>& p){return os<<p.first<<" "<<p.second;}
template<typename K,typename V> ostream& operator << (ostream& os, const map<K,V>& m){bool isF=true;for(auto& p:m){if(!isF)os<<endl;os<<p;isF=false;}return os;}
template<typename T1> ostream& operator << (ostream& os, const tuple<T1>& t){return os << get<0>(t);}
template<typename T1,typename T2> ostream& operator << (ostream& os, const tuple<T1,T2>& t){return os << get<0>(t)<<" "<<get<1>(t);}
template<typename T1,typename T2,typename T3> ostream& operator << (ostream& os, const tuple<T1,T2,T3>& t){return os << get<0>(t)<<" "<<get<1>(t)<<" "<<get<2>(t);}
template<typename T1,typename T2,typename T3,typename T4> ostream& operator << (ostream& os, const tuple<T1,T2,T3,T4>& t){return os << get<0>(t)<<" "<<get<1>(t)<<" "<<get<2>(t)<<" "<<get<3>(t);}
template<typename T> ostream& operator << (ostream& os, const vector<T>& as){for(int i:range(as.size())){if(i!=0)os<<" "; os<<as[i];}return os;}
template<typename T> ostream& operator << (ostream& os, const vector<vector<T>>& as){for(int i:range(as.size())){if(i!=0)os<<endl; os<<as[i];}return os;}

// values
template<typename T> inline T INF(){assert(false);};
template<> inline int INF<int>(){return 1<<28;};
template<> inline ll INF<ll>(){return 1LL<<58;};
template<> inline double INF<double>(){return 1e16;};
template<> inline long double INF<long double>(){return 1e16;};

template<class T> inline T EPS(){assert(false);};
template<> inline int EPS<int>(){return 1;};
template<> inline ll EPS<ll>(){return 1LL;};
template<> inline double EPS<double>(){return 1e-8;};
template<> inline long double EPS<long double>(){return 1e-8;};

// min{2^r | n < 2^r}
template<typename T> T upper_pow2(T n){ T res=1;while(res<n)res<<=1;return res;}
// max{d | 2^d  <= n}
template<typename T> T msb(T n){ int d=62;while((1LL<<d)>n)d--;return d;}

template<typename T,typename U> T pmod(T v,U M){return (v%M+M)%M;}

ll gcd_positive(ll a,ll b) { return b == 0 ? a : gcd_positive(b,a%b); }
ll gcd(ll a,ll b) { return gcd_positive(abs(a), abs(b)); }
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}

template<class Cost> struct Edge{
    int from,to;Cost cost;
    Edge(int from,int to,Cost cost):from(from),to(to),cost(cost){};
    bool operator<(Edge r) const{ return cost<r.cost;}
    bool operator>(Edge r) const{ return cost>r.cost;}
};



// W = 2
// 1 x2
// x3

// W = 3
// 1 x2 x3
// 4 x5
// x7

// W = 4
// 1 x2
// x5

// W = 5
// 1 x2
// 6 x7
// x11

// W = 6
// 1 x2
// x7

// W = 7
// 1   x2  x3
// 8    9  10 x11
// 15  16 x17
// 22 x23
// x29 

// W = 8
//   1 x2  x3   4  x5   6  x7   8
//   9 10 x11  12 x13  14  15  16
// x17 18 x19  20  21  22 x23  24
// 25  26  27  28  29  30 x31  32
// x33 34  35  36 x37  38 x39  40

// W = 9
//   1  x2
//  10 x11
// x19

// W = 10
//   1  x2
// x11

// W = 11
//   1  x2  x3   4  x5   6  x7   8   9  10 x11
//  12 x13  14  15  16 x17  18 x19  20  21  22
// x23  24

// W = 12
//   1  x2  x3   4  x5   6  x7   8   9  10 x11  12
// x13  14  15  16 x17  18 x19  20  21  22 x23  24

class Main{
    public:

    void run(){
        ll N;cin >> N;

        if(N>=25){
            cout << 8 << endl;return;
        }

        // N = 4,6,8,9,10,12,14,15,16,18,20,21,22,24
        if(N== 4){
            cout << 3 << endl;return;
        }
        if(N==6){
            cout << 5 <<endl;return;
        }
        if(N==8 || N == 9 || N == 10 || N == 15 || N == 16 || N == 22){
            cout << 7 << endl;return;
        }
        // N = 12,14,18,20,21,24
        if(N==12){
            cout << 11 <<endl;return;
        }
        if(N==14){
            cout << 13 <<endl;return;
        }
        if(N==18){
            cout << 17 <<endl;return;
        }
        if(N==20 || N == 21){
            cout << 19 << endl;return;
        }
        if(N==24){
            cout << 23 << endl;return;
        }
    }
};

int main(){
    cout <<fixed<<setprecision(20);
    cin.tie(0);
    ios::sync_with_stdio(false);
    Main().run();
    return 0;
}