VAR
 X,dX,S:REAL;
Function ff(xf:Real):Real;
 begin
  If (xf<0.0001) or (xf>5.0001) then ff:=0 else
  If (xf>0) and (xf<3.0001) then ff:=9.0 else
  If (xf>3.0001) and (xf<5.0001) then ff:=2.0;
 end;
BEGIN
 S:=0;
 dX:=1.0;
 X:=dX;
 Repeat
  S:=S+ff(X)*dX;
  X:=X+dX;
 Until X>5.0001;
 WriteLn('S= ',S:5:2);
 ReadLn;
END.