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