There will always be one or more students having the second lowest grade.

nested_hacker.py

#https://www.hackerrank.com/challenges/nested-list
#7/2/16

n = int(raw_input())
student = []

for i in range(n):
	
	student.append([raw_input(),float(raw_input())])

student.sort()
scores = set([s[1] for s in student])
score_l = sorted(list(scores))

for z in student:
	if z[1] == score_l[1]:
		print (z[0])