#include <stdio.h>
#include <string>
#include <cstring>
#include <stdlib.h>
#include <math.h>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <list>
#include <iterator>
#pragma warning(disable:4996)
 
typedef long long ll;
#define MIN(a, b) ((a)>(b)? (b): (a))
#define MAX(a, b) ((a)<(b)? (b): (a))
#define LINF 9223300000000000000
#define INF 2140000000
#define MOD 1000000007
using namespace std;

int main(int argc, char* argv[])
{
    ll n;
    scanf("%lld", &n);
    
    ll a[]={0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 20};

    long m = sizeof(a)/sizeof(ll);
    if(n<m) {
        printf("%lld\n", a[n]);
    }
    

    return 0;
}