thanks you all.

but as you mentioned by using "String" way. how could I let user input a two-digit nubmer and then reverse it?

how do i read a string, such as "56", seperately? I mean, let a integer x = 5, and another int y = 6. thanks again

All I mean is using c language. I tried many times, mession failed!! (Mession Impossible 3!! ^&^)