import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class q15439 {
public static void main(String[] args) throws Exception {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
int N = Integer.parseInt(br.readLine());
if(N == 1) {
N = 0;
}
else {
N *= N-1;
}
bw.write(N+"");
bw.flush();
}
}