B'Luntik came out for a morning stroll and found an array a of length n . He calculated the sum s of the elements of the array ( s= sum_{i=1}^{n} a_i ). Luntik calls a subsequence of the array a nearly full if the sum of the numbers in that subsequence is equal to s-1 . Luntik really wants to know the number of nearly full subsequences of the array a . But he needs to come home so he asks you to solve that problem! A sequence x is a subsequence of a sequence y if x can be obtained from y by deletion of several (possibly, zero or all) elements. The first line contains a single integer t ( 1 <= t <= 1000 ) -- the number of test cases. The next 2 cdot t lines contain descriptions of test cases. The description of each test case consists of two lines. The first line of each test case contains a single integer n ( 1 <= n <= 60 ) -- the length of the array. The second line contains n integers a_1, a_2, ldots, a_n ( 0 <= a_i <= 10^9 ) -- the elements of the array a . For each test case print the number of nearly full subsequences of the array. In the first test case, s=1+2+3+4+5=15 , only (2,3,4,5) is a nearly full subsequence among all subsequences, the sum in it is equal to 2+3+4+5=14=15-1 . In the second test case, there are no nearly full subsequences. In the third test case, s=1+0=1 , the nearly full subsequences are (0) and () (the sum of an empty subsequence is 0 ). '...