program Ural_1064(Input, Output);
const
MaxN = 10000;
type
TIndex = Longint;
TRange = array[1..MaxN] of record
Left, Right: TIndex;
end;
var
F: TRange;
function BinarySearch(l, r, X, H: TIndex): Boolean;
var
i: TIndex;
begin
BinarySearch := false;
i := 0;
while (i < H) and (l begin
Inc(i);
if X > (l + r) div 2 then
l := (l + r) div 2 + 1
else if X < (l + r) div 2 then
r := (l + r) div 2 - 1
else
begin
if i = H then
BinarySearch := true;
Exit;
end;
end;
end;
procedure Main;
var
InRange: Boolean;
N, H, K, Last: TIndex;
i: TIndex;
begin
Readln(N, H);
Last := -1;
InRange := false;
K := 0;
for i := N + 1 to MaxN do
if BinarySearch(0, i - 1, N, H) then
begin
if not InRange then
begin
InRange := true;
Last := i;
end;
end
else
begin
if InRange then
begin
InRange := false;
Inc(K);
F[K].Left := Last;
F[K].Right := i - 1;
end;
end;
if InRange then
begin
Inc(K);
F[K].Left := Last;
F[K].Right := MaxN;
end;
Writeln(K);
for i := 1 to K do
Writeln(F[i].Left, ' ', F[i].Right);
end;
begin
{ Assign(Input, 'i.txt');
Reset(Input);
Assign(Output, 'o.txt');
Rewrite(Output); }
Main;
{ Close(Input);
Close(Output); }
end.
