Improve number flipping
The number flipping doesn't handle the cases where the line contains only numbers and spaces or punctuation like the following cases:
normal: 91 04 25 53 50
flipped: 19 40 52 35 05
normal: 22 04 25 53 50
flipped: 22 40 52 35 05
normal: 05.24.12.34.55
flipped: 50.42.21.43.55
and this shouldn't be the case so this will be fixed in this issue