import sys
a = []
m = int(input())
for line in sys.stdin:
    a.append(line.strip())

n = len(a) 
c = [""] * n

for i in range(m, n - 1):
    for j in range(n - 2, i - 1, -1):
        __________
        if a[k] < a[j]:
            a[k], a[j] = a[j], a[k]
i = 0
__________
for k in range(0, n):
    if j >= n:
        c[k] = a[i]
        i += 1
    elif __________:
        c[k] = a[i]
        i += 1
    else:
        c[k] = a[j]
        j += 1
best = "无"
for i in range(__________):
    if c[i] == c[i + n // 2]:
        best = c[i]
        break
print(best)
for i in c:
    print(i)