#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, 22, 24, 26, 28, 30, 32, 34, 36, 38, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 117, 119, 121, 123, 125};

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

    return 0;
}