program project1;
var f:array[0..60,0..60] of longint;
    t:longint;
procedure init;
begin
     assign(input,'piggy.in');reset(input);
     assign(output,'piggy.out');rewrite(output);
     read(t);
end;
function dfs(n,m:longint):longint;
begin
     if f[n,m]>0 then exit(f[n,m]);
     if (n=m)or(m=1) then begin f[n,m]:=1;exit(1);end;
     f[n,m]:=dfs(n-1,m);
     f[n,m]:=f[n,m]*m;
     f[n,m]:=f[n,m]+dfs(n-1,m-1);
     exit(f[n,m]);
end;
procedure main;
var tt,n,m:longint;
begin
     for tt:=1 to t do
     begin
          read(n,m);
          if n<m then writeln(0) else
               writeln(dfs(n,m));
     end;
     close(input);
     close(output);
end;
begin
     init;
     main;
end.