MODULE Binomial;
IMPORT
  Out;

PROCEDURE For*(n,k: LONGINT): LONGINT;
VAR
  i,m,r: LONGINT;

BEGIN
  ASSERT(n > k);
  r := 1;
  IF k > n DIV 2 THEN m := n - k ELSE m := k END;
  FOR i := 1 TO m DO
    r := r * (n - m + i) DIV i
  END;
  RETURN r
END For;

BEGIN
  Out.Int(For(5,2),0);Out.Ln
END Binomial.