import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(readline())
ques = readlines()

cand = set(range(10))
for q in ques:
    *a,r = q.split()
    se = set(map(int,a))
    if r == b'YES':
        cand &= se
    else:
        cand -= se

answer = cand.pop()
print(answer)