Buggy python submission (verdict: Time Limit Exceeded):
import sys
import math
import itertools as it
def i():return int(sys.stdin.readline().replace("\n",""))
def i2():return map(int,sys.stdin.readline().replace("\n","").split())
def s():return str(sys.stdin.readline().replace("\n",""))
def l():return list(sys.stdin.readline().replace("\n",""))
def intl():return [int(k) for k in sys.stdin.readline().replace("\n","").split()]
def lx():return list(map(lambda x:int(x)*-1,sys.stdin.readline().replace("\n","").split()))
def t():return tuple(map(int,sys.stdin.readline().replace("\n","").split()))

if __name__ == "__main__":pass
n = i()
s = [input() for _ in range(n)]
s.sort()
ss = list(set(s))
ss.sort()
a = [0]*len(ss)
i = 0
while n-1 > i:
    if s[i] == s[i+1]:
        a[ss.index(s[i])] += 1
        i += 1
    else:
        i += 1
m = max(a)
for k in range(len(a)):
    if a[k] == m:
        print(ss[k])


Fixed submission:
import sys
import math
import itertools as it
def i():return int(sys.stdin.readline().replace("\n",""))
def i2():return map(int,sys.stdin.readline().replace("\n","").split())
def s():return str(sys.stdin.readline().replace("\n",""))
def l():return list(sys.stdin.readline().replace("\n",""))
def intl():return [int(k) for k in sys.stdin.readline().replace("\n","").split()]
def lx():return list(map(lambda x:int(x)*-1,sys.stdin.readline().replace("\n","").split()))
def t():return tuple(map(int,sys.stdin.readline().replace("\n","").split()))

if __name__ == "__main__":pass
n = i()
s = [input() for _ in range(n)]
s.sort()
ss = list(set(s))
ss.sort()
a = [0]*len(ss)
i = 0
j = 0
while n-1 > i:
    if s[i] == s[i+1]:
        a[j] += 1
        i += 1
    else:
        i += 1
        j += 1
m = max(a)
for k in range(len(a)):
    if m == a[k]:
        print(ss[k])

Buggy python submission (verdict: Time Limit Exceeded):
import sys
import math
import itertools as it
def i():return int(sys.stdin.readline().replace("\n",""))
def i2():return map(int,sys.stdin.readline().replace("\n","").split())
def s():return str(sys.stdin.readline().replace("\n",""))
def l():return list(sys.stdin.readline().replace("\n",""))
def intl():return [int(k) for k in sys.stdin.readline().replace("\n","").split()]
def lx():return list(map(lambda x:int(x)*-1,sys.stdin.readline().replace("\n","").split()))
def t():return tuple(map(int,sys.stdin.readline().replace("\n","").split()))

if __name__ == "__main__":pass
n = i()
s = [input() for _ in range(n)]
s.sort()
ss = list(set(s))
ss.sort()
a = [0]*len(ss)
i = 0
while n-1 > i:
    if s[i] == s[i+1]:
        a[ss.index(s[i])] += 1
        i += 1
    else:
        i += 1
m = max(a)
for k in range(len(a)):
    if a[k] == m:
        print(ss[k])

Fixed submission:
import sys
import math
import itertools as it
def i():return int(sys.stdin.readline().replace("\n",""))
def i2():return map(int,sys.stdin.readline().replace("\n","").split())
def s():return str(sys.stdin.readline().replace("\n",""))
def l():return list(sys.stdin.readline().replace("\n",""))
def intl():return [int(k) for k in sys.stdin.readline().replace("\n","").split()]
def lx():return list(map(lambda x:int(x)*-1,sys.stdin.readline().replace("\n","").split()))
def t():return tuple(map(int,sys.stdin.readline().replace("\n","").split()))

if __name__ == "__main__":pass
n = i()
s = [input() for _ in range(n)]
s.sort()
ss = list(set(s))
ss.sort()
a = [0]*len(ss)
i = 0
j = 0
while n-1 > i:
    if s[i] == s[i+1]:
        a[j] += 1
        i += 1
    else:
        i += 1
        j += 1
m = max(a)
for k in range(len(a)):
    if m == a[k]:
        print(ss[k])