var
  n,m,i,j:longint;
  f:array[0..1000,0..1000]of longint;
  
function min(x,y:longint):longint;
begin
     if x<y then exit(x);
		 exit(y);
end;

begin
  assign(input,'permutation.in'); reset(input);
  assign(output,'permutation.out'); rewrite(output);
  n:=1000;
  m:=1000;
  for i:=1 to n do
   for j:=0 to m do
   begin
     f[i,j]:=0;
     if j=0 then f[i,j]:=1;
   end;
  for i:=2 to n do
   for j:=1 to min(i-1,m) do
   begin
     if j=i-1 then f[i,j]:=1
     else f[i,j]:=(f[i-1,j-1]*(i-j)+f[i-1,j]*(j+1)) mod 2007;
   end;
   repeat
      readln(n,m);
      writeln(f[n,m]);
  until eof;
  close(input);
  close(output);
end.