n=int(input())
l=[input().split() for i in range(n)]
s=set([i for i in range(10)])
for i in range(n):
  if l[i][-1]=='YES':
    L=[]
    for j in range(4):
      L.append(int(l[i][j]))
    for j in range(10):
      if j not in L:
        if j in s:
          s.remove(j)
  else:
    for j in range(4):
      if int(l[i][j]) in s:
        s.remove(int(l[i][j]))
s=list(s)
print(s[0])