# solution of task F(air coins) written by Monika

from sys import stdin
data = stdin.read().split() 
T, data = int(data[0]), data[1:]

for t in range(T):
    N, fair, biased = int(data[0]), 0, 0
    for coin in data[1:N+1]:
        if coin=='0.500000': fair += 1
        else: biased += 1
    data = data[N+1:]
    print ( (2**biased) * ((2**fair)-1) )