Sorting list of lists with string and int

[Otbredbaron]

So I'm trying to solve this exercise: https://open.kattis.com/problems/cups

Although the problem is simple and does not require much work I'd like to improve my code because it looks pretty bad:

#!/usr/bin/python3

n = int(input())

a = [input().split() for i in range(n)]

for i in a:
    if(i[0].isdigit()):
        i[0] = int(i[0])/2
        i[1], i[0] = i[0], i[1]
    elif(i[1].isdigit()):
        i[1] = int(i[1])

a.sort(key=lambda x: x[1])
[print(i[0]) for i in a]

The main concern is that I don't know if the string will be in a form int string or string int so I need to check for it.