currentPopulation = 307357870

yearToSeconds = 365*24*60*60

yearsToCalculate = int(input("Enter the number of desired years"))

if yearsToCalculate == -1:
    sys.exit("WRONG INPUT")

populationAfterYears = float(currentPopulation + ((yearsToCalculate*yearToSeconds)/7) + ((yearsToCalculate*yearToSeconds)/35) - ((yearsToCalculate*yearToSeconds)/13))

print("Updated population:", populationAfterYears)