var s,before,bf,i,n:longint;
    max:comp;
begin
 readln(n);
 readln(bf);
 readln(before);
 max:=before*1.0-bf;
 s:=1;
 for i:=3 to n do
  begin
   readln(bf);
   if bf*1.0-before>max then
    begin
     s:=i-1;
     max:=bf*1.0-before;
    end;
   before:=bf;
  end;
 writeln(s,' ',s+1);
end.

For some strange reason, only c++ sources get AC

Why ?