N=int(input())
T=[]
S=[]
ans=""
Ans=[]
for i in range(N):
    t,s=map(str,input().split())
    T.append(t)
    S.append(s)

for i in range(len(T)):
    if T[i] == "0":
        Ans.append(S[i])
    else:
        Ans.insert(0,S[i])

for i in range(len(Ans)):
    ans+=Ans[i]
print(ans)