PROGRAM POWERDEF(OUTPUT);
(*# E+ *)
FUNCTION POWER(VAR X:REAL;VAR Y:INTEGER):REAL;
VAR Z:REAL;
BEGIN
Z:=1;
WHILE Y>0 DO
 BEGIN
  WHILE NOT ODD(Y) DO
    BEGIN
    Y:=Y DIV 2;
    X:=SQR(X)
    END;
  Y:=Y-1;Z:=X*Z
  END;
POWER:=Z
END;
BEGIN
END.