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();
		int count = 0;
		if (n > 1) {
			count += (n * (n - 1)) / 2;
		}
		if (m > 1) {
			count += (m * (m - 1)) / 2;
		}
		System.out.println(count);
		sc.close();
	}

} 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();
		int count = 0;
		if (n > 1) {
			count += (n * (n - 1)) / 2;
		}
		if (m > 1) {
			count += (m * (m - 1)) / 2;
		}
		System.out.println(count);
		sc.close();
	}

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

} public class Main {

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

} 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();
		int count = 0;
		if (n > 1) {
			count += (n * (n - 1)) / 2;
		}
		if (m > 1) {
			count += (m * (m - 1)) / 2;
		}
		System.out.println(count);
		sc.close();
	}

}