n = int(input())
e = [[i for i in input().split()] for _ in range(n)]

ans = [True] * 10

for ee in e:
  if ee[4] == "YES":
    b = [False for _ in range(10)]
  else:
    b = [True for _ in range(10)]
  for i in range(4):
    if ee[4] == "YES":
      b[int(ee[i])] = True
    else:
      b[int(ee[i])] = False
  for i in range(10):
    ans[i] &= b[i]
print(ans.index(True))