import java.io.*;
import java.util.*;

class Main
{
    public static void main(String args[])throws Exception
    {
        BufferedReader bu=new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb=new StringBuilder();
        String s[]=bu.readLine().split(" ");
        int n=Integer.parseInt(s[0]),h=Integer.parseInt(s[1]),w=Integer.parseInt(s[2]);
        long ans=1l*(n/2)*(n-n/2)*(h+w-2);
        System.out.print(ans);
    }
}