program fall;
var f:array [1..55,1..55] of qword;
    t,n,m,i,j,k:longint;
begin
 assign(input,'piggy.in');
 assign(output,'piggy.out');
 reset(input);
 rewrite(output);
 for i:=1 to 55 do begin f[i,i]:=1; f[i,0]:=0; end;
  for j:=1 to 55 do
   for i:=j+1 to 55 do
    f[i,j]:=f[i-1,j-1]+j*f[i-1,j];
 readln(t);
 for k:=1 to t do
  begin
   readln(n,m);
   writeln(f[n,m]);
  end;
 close(input);
 close(output);
end.