import java.util.*;

public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    }
} Main public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    } main {
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc int M = sc.nextInt(); M sc.nextInt() sc.nextInt sc System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2) System.out.println System.out System System.out (N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2 (N-1)*(N-1+1)/2 (N-1)*(N-1+1) (N-1) N 1 (N-1+1) N-1 N 1 1 2 (M-1)*(M-1+1)/2 (M-1)*(M-1+1) (M-1) M 1 (M-1+1) M-1 M 1 1 2 String[] args args public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    }
} public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    	 int N = sc.nextInt();
      	 int M = sc.nextInt();
		
        	System.out.println((N-1)*(N-1+1)/2+(M-1)*(M-1+1)/2);
    }
}