import sys
input = sys.stdin.readline

N = int(input())
TSs =[input().split() for _ in range(N)]

f = []
r = []

for TS in TSs:
    if TS[0] == '0':
        r.append(TS[1])
    else:
        f.append(TS[1])
res = ''.join(reversed(f)) + ''.join(r)
print(res)