N = int(input())
L = [[str(i), 0] for i in range(10)]
d = dict(L)

for _ in range(N):
    I = input().split()
    for i in range(4):
        if I[-1] == 'NO':
            d[I[i]] -= 1
        else:
            d[I[i]] += 1

print(max(d, key = d.get))