import sys,collections
sys.setrecursionlimit(10**7)
def Is(): return [int(x) for x in sys.stdin.readline().split()]
def Ss(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def S(): return input()

n = I()
ans = ""
for _ in range(n):
    ans += S()
print(ans)