
    In a social networking platform's friend recommendation system, find the user ID of the most compatible potential connection from a list of user-compatibility pairs. Each pair consists of a user ID and their calculated compatibility score (where a lower score indicates higher compatibility), and you need to return the user ID from the pair that has the lowest compatibility score.
    

    
from operator import itemgetter

def index_minimum(test_list):
    """
    In a social networking platform's friend recommendation system, find the user ID of the most compatible potential connection from a list of user-compatibility pairs. Each pair consists of a user ID and their calculated compatibility score (where a lower score indicates higher compatibility), and you need to return the user ID from the pair that has the lowest compatibility score.
    

    """
from operator import itemgetter

def index_minimum(test_list):
    """
    In a social networking platform's friend recommendation system, find the user ID of the most compatible potential connection from a list of user-compatibility pairs. Each pair consists of a user ID and their calculated compatibility score (where a lower score indicates higher compatibility), and you need to return the user ID from the pair that has the lowest compatibility score.
    

    """
    res = min(test_list, key=itemgetter(1))[0]
    return res