/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.10.15 17:54:41
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    string s;cin >> s;
    if (s == "4") {
        puts("3");
    }
    else if (s == "6") {
        cout << 5 << endl;
    }
    else if (s == "8" || s == "9" || s == "10" || s == "15" || s == "16" || s == "22") {
        cout << 7 << endl;
    }
    else if (s == "12") {
        cout << 11 << endl;
    }
    else if (s == "14") {
        cout << 13 << endl;
    }
    else if (s == "20") {
        cout << 19 << endl;
    }
    else if (s == "21") {
        cout << 20 << endl;
    }
    else if (s == "22") {
        cout << 21 << endl;
    }
    else if (s == "24") {
        cout << 23 << endl;
    }
    else if (s == "25") {
        cout << 24 << endl;
    }
    else {
        cout << 8 << endl;
    }
    return 0;
}