var f,g:text;
    ct,j,k,i,n:integer;
    v:array[1..800] of integer;
    st:array[1..3] of integer;
procedure prob;
begin
if (st[1]+st[2] >= st[3]) or (st[1]+st[3] >= st[2]) or (st[2]+st[3] >= st[1]) then
ct:=ct+1;
end;




BEGIN
assign(f,'nrtri.in');
reset(f);ct:=0;
read(f,n);readln(f);
for i:=1 to n do
read(f,v[i]);
close(f);

for i:=1 to n do
for j:=1 to n do
for k:=1 to n do
if (i<j) and (j<k) then
begin
st[1]:=v[i];
st[2]:=v[j];
st[3]:=v[k];
prob;
end;

assign(g,'nrtri.out');
rewrite(g);
writeln(g,ct);
close(g);
END.