import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  }
} import java.util.Scanner; Scanner 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();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  } main {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  } 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 sc.close() sc.close sc int answer = 0; answer 0 answer += (n * (n - 1)) / 2 answer (n * (n - 1)) / 2 (n * (n - 1)) n (n - 1) n 1 2 answer += (m * (m - 1)) / 2 answer (m * (m - 1)) / 2 (m * (m - 1)) m (m - 1) m 1 2 System.out.println(answer) System.out.println System.out System System.out answer 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();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  }
} public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  }
} Main
import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    sc.close();
    int answer = 0;
    answer += (n * (n - 1)) / 2;
    answer += (m * (m - 1)) / 2;
    System.out.println(answer);
  }
}