#include <stdio.h>
#include <malloc.h>
#include <time.h>
#include <math.h>

#define BASE 1000000000ll
#define N_BASE 9

void div(int *X,int size,int y) // X /= y;
{
        long long carry = 0;
        for(int i = 0;i < size;i++)
        {
                carry += X[i];
                X[i] = (long long)carry / y;
                carry = (carry % y) * BASE;
        }
}
void mul(int *X,int size,int y) // X *= y;
{
        long long carry = 0;
        for(int i = size;i >= 0;i--)
        {
                carry += X[i]*((long long)y);
                X[i] = (int)(carry % BASE) ;
                carry /= BASE;
        }
}
void write(int *X,int size)
{
        for(int i = 0;i < size;i++)
        {
                printf("%09i",X[i]);
        }
}
int main()
{
        int num;
        scanf("%i",&num);
        clock_t timer = clock();
        int m = num/9 + 10;
        int *X = (int*)malloc(sizeof(int)*m);
        X[0] = BASE/10;
        int max = (int)(3.35*num + 2);
        for(int i = m - 1;i > 0;i--) X[i] = 0;
        for(int i = max;i > 0;i--)
        {
                if(i % (int)sqrt(max) == 0) printf("%i\n", i);
                div(X,m,2*i+1);
                mul(X,m,i);
                X[0] += BASE/10;
        }
        mul(X,m,2);
        write(X,m - 10);
        printf("\n\nTime = %.3f sec",(double)(clock() - timer)/1000.0 );
        getchar();
        getchar();
}