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