program Permutations (input, output);

{  Pascal main program using assembly language
   function Factorial to calculate P(N,R) }

var  N, R, NPR:  integer;

function Factorial (K:  integer):  integer;  external;

begin
  writeln ('Enter values of N and R');
  readln (N, R);
  NPR := Factorial(N) div Factorial(N - R);
  writeln ('Number of permutations = ', NPR);
end.