type coord=record
x,y:longint
end;
var a:array[1..1000] of coord;
i,n,j:integer;
k,l,nrpat,max,min:integer;
difx,dify:longint;
xx,yy:real;
f,g:text;
begin
assign(f,'patrate3.in');
assign(g,'patrate3.out');
reset(f);
rewrite(g);
read(f,n);
for i:=1 to n do begin
read(f,xx,yy);
a[i].x:=round(10000*xx);
a[i].y:=round(10000*yy);
end;
for i:=1 to n-3 do
for j:=i+1 to n do begin
difx:=a[i].x-a[j].x;
dify:=a[i].y-a[j].y;
for k:=j+1 to n do begin
if (a[k].x=a[j].x-dify) and (a[k].y=a[j].y+dify) then begin
for l:=j+1 to n do if (a[l].x-a[k].x=difx) and (a[l].y-a[k].y=dify) then
nrpat:=nrpat+1;
end;
if (a[k].x=a[j].x+dify) and (a[k].y=a[j].y-dify) then begin
for l:=j+1 to n do if (a[l].x-a[k].x=difx) and (a[l].y-a[k].y=dify) then
nrpat:=nrpat+1;
end;
end;
end;
writeln(g,nrpat);
close(g);
close(f);
end.