program pailie;
var
  n,k,i,j:longint;
  f:array[1..100,0..100]of longint;
begin
  assign (input,'permutation.in');
  reset (input);
  assign (output,'permutation.out');
  rewrite (output);
    n:=100;
    for i:=1 to n do
      f[i,0]:=1;
    for i:=1 to n do
      for j:=1 to i-1 do
      begin
        f[i,j]:=f[i-1,j]*(j+1)+f[i-1,j-1]*(i-j);
        f[i,j]:=f[i,j] mod 2007
      end;
    repeat
      readln (n,k);
      writeln (f[n,k]);
    until eof;
  close (input);
  close (output)
end.