A10X2A3A14
0123456789*89a*bcdefghijklmn
Benchmark: timing 1000000 iterations of substr, unpack...
    substr: 12 wallclock secs (12.80 usr + -0.02 sys = 12.78 CPU) @ 78241.14/s (n=1000000)
    unpack:  9 wallclock secs ( 9.00 usr +  0.00 sys =  9.00 CPU) @ 111098.77/s (n=1000000)