http://amacar.tk/generateImage/index.php?VALUE=10

# Future population estimation
# Your name

currentPopulation = 307357870
birth = 7
death = 13
immigrant = 35

yearsPredicting = int(raw_input("For how many years you want prediction? "))

#convert years to seconds
yearsInSeconds = yearsPredicting * 365 * 24 * 60 * 60

#take float values
futurePopulation = currentPopulation + float(yearsInSeconds) / birth
futurePopulation -= float(yearsInSeconds) / death
futurePopulation += float(yearsInSeconds) / immigrant

#we can't have "half" of person, so we take lower bound
futurePopulation = int(futurePopulation)

print "Future population estimation is: ", futurePopulation