dalex

var
    a, b, n, m, ax, ay, bx, by: longint;

begin
    read(n, m, a, b);
    dec(n);
    dec(a);
    dec(b);

    ax := a mod m;
    ay := a div m;
    bx := b mod m;
    by := b div m;

    if (ay = by) or ((ax = 0) and (b = n)) or ((ax = 0) and (bx = m-1)) then begin
        writeln(1);
        halt;
    end;

    if (ay+1 = by) or (ax = 0) or (bx = m-1) or (b = n) or (ax-1 = bx) then begin
        writeln(2);
        halt;
    end;

    writeln(3);
end.