CF1582B.Luntik and Subsequences

传统题 时间 2000 ms 内存 256 MiB 4 尝试 1 已通过 1 标签

Luntik and Subsequences

Luntik came out for a morning stroll and found an array aa of length nn. He calculated the sum ss of the elements of the array (s=umi=1nais= um_{i=1}^{n} a_i). Luntik calls a subsequence of the array aa nearly full if the sum of the numbers in that subsequence is equal to s1s-1.

Luntik really wants to know the number of nearly full subsequences of the array aa. But he needs to come home so he asks you to solve that problem!

A sequence xx is a subsequence of a sequence yy if xx can be obtained from yy by deletion of several (possibly, zero or all) elements.

Input

The first line contains a single integer tt (1t10001 \le t \le 1000) — the number of test cases. The next 2t2 \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 nn (1n601 \le n \le 60) — the length of the array.

The second line contains nn integers a1,a2,,ana_1, a_2, \ldots, a_n (0ai1090 \le a_i \le 10^9) — the elements of the array aa.

Output

For each test case print the number of nearly full subsequences of the array.

Note

In the first test case, s=1+2+3+4+5=15s=1+2+3+4+5=15, only (2,3,4,5)(2,3,4,5) is a nearly full subsequence among all subsequences, the sum in it is equal to 2+3+4+5=14=1512+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=1s=1+0=1, the nearly full subsequences are (0)(0) and ()() (the sum of an empty subsequence is 00).

Samples

5
5
1 2 3 4 5
2
1000 1000
2
1 0
5
3 0 2 1 1
5
2 1 0 3 0
1
0
2
4
4

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