import java.util.Scanner;

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

public class Main{
  public static void main(String[] args){
  Scanner scanner = new Scanner(System.in);
    int n = scanner.nextInt();
    int m = scanner.nextInt();
    int ans = 0;
    if(n > 1){
      ans += (n * (n -1))/2;
    }
    if(m > 1){
      ans += (m * (m - 1))/2;
    }
    System.out.println(ans);
  }
}