Scenes From a Memory

Description:

Input:

Each test contains multiple test cases.

The first line contains one positive integer $$$t$$$ ($$$1 \le t \le 10^3$$$), denoting the number of test cases. Description of the test cases follows.

The first line of each test case contains one positive integer $$$k$$$ ($$$1 \le k \le 50$$$) — the number of digits in the number.

The second line of each test case contains a positive integer $$$n$$$, which doesn't contain zeros in decimal notation ($$$10^{k-1} \le n < 10^{k}$$$). It is guaranteed that it is always possible to remove less than $$$k$$$ digits to make the number not prime.

It is guaranteed that the sum of $$$k$$$ over all test cases does not exceed $$$10^4$$$.

Output:

For every test case, print two numbers in two lines. In the first line print the number of digits, that you have left in the number. In the second line print the digits left after all delitions.

If there are multiple solutions, print any.

Sample Input:

7
3
237
5
44444
3
221
2
35
3
773
1
4
30
626221626221626221626221626221

Sample Output:

2
27
1
4
1
1
2
35
2
77
1
4
1
6

Note:

In the first test case, you can't delete $$$2$$$ digits from the number $$$237$$$, as all the numbers $$$2$$$, $$$3$$$, and $$$7$$$ are prime. However, you can delete $$$1$$$ digit, obtaining a number $$$27 = 3^3$$$.

In the second test case, you can delete all digits except one, as $$$4 = 2^2$$$ is a composite number.