N = int(input())
T = []
S = []
Ans = []

for _ in range(N):
    t, s = map(str, input().split())
    T.append(t)
    S.append(s)

for i in range(N):
    if T[i] == '0':
        Ans.append(S[i])
    else:
        Ans.insert(0, S[i])

print(''.join(Ans))