Program puncte;
const INF=999999999;
type coordonata = record
                        x : longint;
                        y : longint;
                  end;
function panta (x,y,x1,y1 : longint) : real;
   begin
         if (x1-x<>0) then panta:=(y1-y)/(x1-x)
         else panta:=INF;
   end;

var M : array [1..1010,1..1010] of real;
    Viz : array [1..1010,1..1010] of 0..1;
    K :array [1..1010] of coordonata;
    i,n,j,l,p,t :longint;

begin
    assign(input,'trapez.in'); reset(input);
    assign(output,'trapez.out'); rewrite(output);
    readln(n);
    for i:=1 to n do readln(K[i].x,K[i].y);

    for i:=1 to n do
      for j:=1 to n do
                 M[i,j]:=panta(k[i].x,k[i].y,k[j].x,k[j].y);

  for i:=1 to n do
    for j:=1 to n do viz[i,j]:=0;

    for i:=1 to n do
      for j:=1 to n do begin
       if viz[i,j]=0 then
          if (M[i,j]<>INF) then begin
                                    viz[i,j]:=1;
                for l:=1 to n do
                      for p:=1 to n do

     if (M[l,p]=M[i,j]) and
           (viz[l,p]=0) and
                 (i<>l) and
                 (i<>p) and
                 (j<>l) and
                 (j<>p) then begin
                             t:=t+1;
                             viz[l,p]:=1;
                        end;      end;
                       end;


     writeln(t div 2);


    close(output);
    close(input);
end.