N = int(input())

ans = [1] * 10

for i in range(N):
    
    A, B, C, D, R = input().split()
    
    A = int(A)
    
    B = int(B)
    
    C = int(C)
    
    D = int(D)
    
    if R == 'NO':
        
        ans[A] = 0
        
        ans[B] = 0
        
        ans[C] = 0
        
        ans[D] = 0
        
    else:
        
        for i in range(10):
            
            if not(i in (A, B, C, D)):
                
                ans[i] = 0
                
print(ans.index(1))