class Point {
        int x;
        int y;

        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }
    }

    void solve() {
        int n = in.nextInt();
        Point[] points = new Point[n];
        for (int i = 0; i < n; i++) {
            int x = in.nextInt();
            int y = in.nextInt();
            points[i] = new Point(x, y);
        }
        Arrays.sort(points, (p1, p2) -> Integer.compare(p1.x, p2.x));
        long countx = 0;
        long ans = 0;
        for (int i = 1; i < n; i++) {
            if (points[i].x == points[i - 1].x) {
                countx++;
                if (i == n - 1){
                    ans += (countx * (countx + 1)) / 2;
                    countx = 0;
                }

            } else {
                ans += (countx * (countx + 1)) / 2;
                countx = 0;
            }
        }
        Arrays.sort(points, (o1, o2) -> {
            if (o1.y < o2.y)
                return -1;
            if (o1.y > o2.y)
                return 1;
            if (o1.x < o2.x)
                return -1;
            if (o1.x > o2.x)
                return 1;
            return 0;
        });
        long county = 0;
        long dec = 0;
        for (int i = 1; i < n; i++) {
            if (points[i].y == points[i - 1].y) {
                county++;
                if (points[i].x == points[i - 1].x) {
                    dec++;
                }
                if (i == n - 1){
                    ans += (county * (county + 1)) / 2 - (dec*(dec+1))/2;
                    county = 0;
                    dec = 0;
                }
            } else {
                ans += (county * (county + 1)) / 2 - (dec*(dec+1))/2;
                county = 0;
                dec = 0;
            }
        }
        out.print(ans);
    }