Unknown error, possible formula too long.

Hello everyone. I have this problem with EXCEL 2003: i enter this formula =if(D2>=275;10;if(D2>=265;9;if(D2>=255;8;if(D2>=250;7;if(D2>=245;6;if(D2>=235;5;if(D2>=230;4;if(D2>=220;3;if(D2>=215;2;if(D2>=200;1;0)))))))))) and it gives me an error. When i shorten this formula it works perfect. I know that excel allows 1024 characters long formulas, my formula is not that long, how do you think where could be a problem in this formula? I tried other formulas about same size and same error shows up.