872 B | 872 chars
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
# sys.setrecursionlimit(10**7)
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def gcd(a, b): return gcd(b, a % b) if b > 0 else a
def lcm(a, b): return a * b // gcd(a, b)
def solve():
n = ii()
l = [inp() for _ in range(n)]
mx = max([len(i) for i in l])
ans = ""
for i in range(mx):
sm = 0
cnt = 0
for s in l:
if i < len(s):
sm += ord(s[i])
cnt += 1
ans += chr(sm // cnt)
p(ans)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()