N = int(input())
ls1 = []
ls2 = []
for i in range(N):
    s = input().split()
    if s[0] == "0":
        ls2.append(s[1])
    else:
        ls1.append(s[1])
ls1.reverse()
ans = ""
for i in range(len(ls1)):
    ans += ls1[i]
for j in range(len(ls2)):
    ans += ls2[j]
print(ans)