10
-2 1
2 -2
-1 -2
0 0
2 -1
0 -2
2 2
0 2
-1 -1
1 -2
 40
-8 24
2 -1
1 -18
72 -70
5 -4
-308 436
-19 40
36 -35
-178 265
-1 2
-7 30
-1 0
3 -2
200 -285
17 -16
-35 74
0 -4
-86 106
-1 4
-7 6
0 1
-5 4
-2 3
6 -5
-4 5
181 -262
76 -118
0 0
-7 18
-58 104
-5 6
-6 12
-3 4
1 0
11 -10
-86 130
-3 6
153 -236
-183 270
-33 64
 5
0 -1
0 -2
0 -3
0 -4
0 -5
 10
0 1
-1 -1
1 1
-1 0
1 -1
-2 -1
-2 2
-2 0
0 -2
0 -1
 20
-1 18
-2 5
-5 4
2 -33
9 -18
0 0
11 -22
2 0
-1 2
-4 41
1 6
1 -2
6 -12
0 1
-3 6
3 -6
3 -8
-1 4
2 -5
1 0
 10
2 1
-1 0
-2 -1
-1 1
0 2
2 -2
0 0
-2 -2
0 -2
-2 1
 20
-3 -3
0 4
-3 1
1 1
-1 2
-4 4
3 -1
-3 0
0 2
4 0
2 3
2 4
4 -3
-4 3
-1 1
1 3
-2 4
1 -2
1 -1
3 0
 3
0 0
0 -1
0 1
 10
2 1
-1 1
0 0
-3 1
-2 -3
-1 -2
-1 -1
1 2
3 -2
0 -2
 3
3 3
1 2
1 1
 4
0 0
1 0
2 0
3 0
 9
1 1
1 0
0 1
0 0
-1 0
-1 1
-1 -1
1 -1
0 -1
 7
1 1
-1 -1
1 0
0 1
-1 0
0 -1
0 0

4
 57
 4
 5
 21
 4
 10
 1
 1
 0
 2
 8
 3

from sys import stdin
def IsOneLine(a,b,c):
	if (b[0]-a[0])*(b[1]-c[1])-(b[1]-a[1])*(b[0]-c[0])==0:
		return True
	return False
def Vid(a,b):
	return pow(pow(a[0]-b[0],2)+pow(a[1]-b[1],2),0.5)
def IsMiddle(a,b,c):
	ret=[]
	ret.append(Vid(a,b))
	ret.append(Vid(a,c))
	ret.append(Vid(b,c))
	ret=sorted(ret,reverse=True)
	if ret[1]==ret[2]:
		return True
	return False



inn = stdin.readlines()
n=int(inn[0])
inn=inn[1:]
mast=[[int(y) for y in x.split()]for x in inn]
mast=sorted(mast,key=lambda a:a[0]+a[1])
count=0
for i in range(len(mast)):
	for j in range(i+1,len(mast)):
		for z in range(j+1,len(mast)):
			if IsOneLine(mast[i],mast[j],mast[z]):
				if IsMiddle(mast[i],mast[j],mast[z]):
					
					count+=1
					break
			if Vid(mast[i],mast[j])<Vid(mast[j],mast[z]):
				break
print count



