Create a function that takes a list containing nested lists as an argument. Each sublist has 2 elements. The first element is the numerator and the second element is the denominator. Return the sum of the fractions rounded to the nearest whole number.
sum_fractions([[18, 13], [4, 5]]) ➞ 2
sum_fractions([[36, 4], [22, 60]]) ➞ 9
sum_fractions([[11, 2], [3, 4], [5, 4], [21, 11], [12, 6]]) ➞ 11
Your result should be a number not string.