For the numbers -13 to -2 use the letters o-z or O-Z
For the number -1 use the space bar
The numbers 0 to 9 correspond to the numbers 0 to 9
For the numbers 10 to 13 use the letters a-d or A-D
For the numbers -13 to -2 use the letters o-z or O-Z
For the number -1 use the space bar
The numbers 1 to 9 correspond to the numbers 1 to 9
For the numbers 10 to 13 use the letters a-d or A-D