# The current volume of a water reservoir (in cubic metres)
reservoir_volume = 4.445 * (10 ** 8)
# The amount of rainfall from a storm (in cubic metres)
rainfall = 5 * ( 10**6)

# decrease the rainfall variable by 10% to account for runoff
rainfall -= (rainfall * 10) /  100
# add the rainfall variable to the reservoir_volume variable
reservoir_volume += rainfall
# increase reservoir_volume by 5% to account for stormwater that flows
# into the reservoir in the days following the storm
reservoir_volume += (reservoir_volume * 5) / 100
# decrease reservoir_volume by 5% to account for evaporation
reservoir_volume -= 1122500
# subtract 2.5 * (10 ** 5) cubic metres from reservoir_volume to account
for water
# that's piped to arid regions.
reservoir_volume -= 2.5 * (10 ** 5)
# print the new value of the reservoir_volume
print(reservoir_volume)