One day Vasya painted a Cartesian coordinate system on a piece of paper and marked some set of points (*x*<sub class="lower-index">1</sub>, *y*<sub class="lower-index">1</sub>), (*x*<sub class="lower-index">2</sub>, *y*<sub class="lower-index">2</sub>), ..., (*x*<sub class="lower-index">*n*</sub>, *y*<sub class="lower-index">*n*</sub>). Let's define neighbors for some fixed point from the given set (*x*, *y*): 
 -  point (*x*', *y*') is (*x*, *y*)'s right neighbor, if *x*' &gt; *x* and *y*' = *y* -  point (*x*', *y*') is (*x*, *y*)'s left neighbor, if *x*' &lt; *x* and *y*' = *y* -  point (*x*', *y*') is (*x*, *y*)'s lower neighbor, if *x*' = *x* and *y*' &lt; *y* -  point (*x*', *y*') is (*x*, *y*)'s upper neighbor, if *x*' = *x* and *y*' &gt; *y* 
We'll consider point (*x*, *y*) from the given set supercentral, if it has at least one upper, at least one lower, at least one left and at least one right neighbor among this set's points.

Vasya marked quite many points on the paper. Analyzing the picture manually is rather a challenge, so Vasya asked you to help him. Your task is to find the number of supercentral points in the given set.
The first input line contains the only integer *n* (1 ≤ *n* ≤ 200) — the number of points in the given set. Next *n* lines contain the coordinates of the points written as "*x* *y*" (without the quotes) (|*x*|, |*y*| ≤ 1000), all coordinates are integers. The numbers in the line are separated by exactly one space. It is guaranteed that all points are different.
8
1 1
4 2
3 1
1 2
0 2
0 1
1 0
1 3
2
5
0 0
0 1
1 0
0 -1
-1 0
1
9
-565 -752
-184 723
-184 -752
-184 1
950 723
-565 723
950 -752
950 1
-565 1
1
25
-651 897
916 897
-651 -808
-748 301
-734 414
-651 -973
-734 897
916 -550
-758 414
916 180
-758 -808
-758 -973
125 -550
125 -973
125 301
916 414
-748 -808
-651 301
-734 301
-307 897
-651 -550
-651 414
125 -808
-748 -550
916 -808
7
1
487 550
0
10
990 -396
990 736
990 646
990 -102
990 -570
990 155
990 528
990 489
990 268
990 676
0
30
507 836
525 836
-779 196
507 -814
525 -814
525 42
525 196
525 -136
-779 311
507 -360
525 300
507 578
507 311
-779 836
507 300
525 -360
525 311
-779 -360
-779 578
-779 300
507 42
525 578
-779 379
507 196
525 379
507 379
-779 -814
-779 42
-779 -136
507 -136
8
25
890 -756
890 -188
-37 -756
-37 853
523 998
-261 853
-351 853
-351 -188
523 -756
-261 -188
-37 998
523 -212
-351 998
-37 -188
-351 -756
-37 -212
890 998
890 -212
523 853
-351 -212
-261 -212
-261 998
-261 -756
890 853
523 -188
9
21
-813 -11
486 254
685 254
-708 254
-55 -11
-671 -191
486 -11
-671 -11
685 -11
685 -191
486 -191
-55 254
-708 -11
-813 254
-708 -191
41 -11
-671 254
-813 -191
41 254
-55 -191
41 -191
5
4
1 0
2 0
1 1
1 -1
0
l=[]
for _ in range(int(input())):
	l.append(list(map(int,input().split())))
r=0
for i in l:
	p=0
	for j in l:
		if i[0]==j[0] and i[1]<j[1]:
			p+=1
		if i[0]==j[0] and i[1]>j[1]:
			p+=1
		if i[0]<j[0] and i[1]==j[1]:
			p+=1
		if i[0]>j[0] and i[1]==j[1]:
			p+=1
		if p==4:
			break
	if p==4:
		r+=1
print(r)