Don't need a language then, just compile down to "return 4". No instructions needed. Without user input it's not really useful. How about returning maximum value of user-privided array of int64 values? If array is static, just return final value and that's all. Smart compiler for the win!

P.S. precomputing even a single int64 space is going to be really really hard, 2^64 possible values is a lot