var
a:array[1..1000] of integer;
b:array [1..2] of integer;
i,j,sum:integer;
begin
for i:=1 to 1000 do 
a[i]:=random(13)-5;
j:=1;
for i:=1 to 1000 do begin
if j=3 then break;
if a[i]>0 then begin b[j]:=i;inc(j);end;
end;
for i:=b[1] to b[2] do
sum:=sum+a[i];
writeln(sum);
end.