N, X, Q = map(int,input().split())
attack = 0
near_attack = 0
for i in range(Q):
    M = int(input())
    F = list(map(int,input().split()))
    umineko = 0
    some_attack = 0
    attacked = set()
    for j in range(M):
        if F[j] == X:
            umineko += 1
            if X not in attacked:
                attacked.add(X)
        else:
            if F[j] in attacked:
                some_attack += 1
            else:
                attacked.add(F[j])
    if umineko > 0:
        attack += 1
    elif some_attack > 0:
        near_attack += 1
ans = 0
ans += attack
ans += near_attack * 0.5
print(ans)