# This time we want to write calculations using functions and get the results. Let's have a look at some examples:

# seven(times(five())) # must return 35
# four(plus(nine())) # must return 13
# eight(minus(three())) # must return 5
# six(divided_by(two())) # must return 3

# Requirements:

# There must be a function for each number from 0 ("zero") to 9 ("nine")
# There must be a function for each of the following mathematical operations: plus, minus, times, dividedBy (divided_by in Ruby and Python)
# Each calculation consist of exactly one operation and two numbers
# The most outer function represents the left operand, the most inner function represents the right operand
# Division should be integer division. For example, this should return 2, not 2.666666...:
# eight(divided_by(three()))

