#include <fstream>
#include <iostream>
#include <queue>
#include <algorithm>
# define inf 1000000

using namespace std;

ifstream f("sortari2.in");
ofstream g("sortari2.out");

int main(){
    int fact = 1, a, b, c, n, nr;
    f >> n;
    for( int i = 2; i <= n; ++i )
        fact = fact * i;
    nr = n * 2 - 1;
    a = 1; b = 1;
    for( int i = 3; i <= nr; ++i ){
        c = a + b;
        b = a;
        a = c;
    }
    g << fact - c;
    return 0;
}