include <bits/stdc++.h>

using namespace std;

define int long long

const int mod = 1e9 + 7; int f[2005];

signed main() {

int n;
cin >> n;

f[1] = 0;
f[2] = 1;
for (int i = 3; i <= n; i++) {
	f[i] = (i - 1) * (f[i - 1] + f[i - 2]) % mod;
}

cout << f[n] << endl;

return 0;

}