Pokéball success rate

catch.py

#!/usr/bin/env python3

from math import sqrt

def main():
    '''Display the probability of successfully capturing a Pokémon.'''

    # Read in the formulae parameters.
    max_hp = int(input('Max HP: '))
    hp = int(input('Remaining HP: '))
    catch_rate = int(input('Catch rate: '))
    ball_modifier = int(input('Ball modifier: '))
    status_modifier = int(input('Status modifier: '))

    # Compute and print the results.
    a = ((((3*max_hp - 2*hp ) * (catch_rate*ball_modifier )) /
            (3*max_hp)) * status_modifier)
    b = 1048560 / sqrt(sqrt(16711680 / a))
    p = ((b+1)/2**16)**4
    print(str(100*p) + '% chance.')

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        exit(0)