As shown in the figure, the square $A B C D$ is at the center of the coordinate axes, and there are the following four operation methods,
$\mathrm{T} 1:$ Counterclockwise rotation by $90^{\circ}$;
T2: Clockwise rotation by $90^{\circ}$;
T3: Flip up and down around the $\mathrm{x}$-axis;
$\mathrm{T} 4$ : Flip left and right around the $\mathrm{Y}$-axis; After four operations, the rectangle coincides with the original, how many different operation methods are there? (The original can also coincide during the operation)
【Answer】 64