NB. The trick is to convert numbers to a common base using
NB. a^b = e^(b * ln(a)), so by comparing the exponents we
NB. avoid calculating the large number

solve =: {{
	>:{.\:{{y*^.x}}/|:1000 2$".>{.|:2000 2$;:fread y
}}

problem99 =: solve 'p099_base_exp.txt'