B'We start with a string s consisting only of the digits 1 , 2 , or 3 . The length of s is denoted by |s| . For each i from 1 to |s| , the i -th character of s is denoted by s_i . There is one cursor. The cursor 's location ell is denoted by an integer in {0, ldots, |s| } , with the following meaning: We denote by s_ text{left} the string to the left of the cursor and s_ text{right} the string to the right of the cursor. We also have a string c , which we call our clipboard, which starts out as empty. There are three types of actions: The cursor initially starts at ell = 0 . Then, we perform the following procedure: You 're given the initial string s and the integer x . What is the length of s when the procedure stops? Since this value may be very large, only find it modulo 10^9 + 7 . It is guaranteed that ell <= |s| at any time. The first line of input contains a single integer t ( 1 <= t <= 1000 ) denoting the number of test cases. The next lines contain descriptions of the test cases. The first line of each test case contains a single integer x ( 1 <= x <= 10^6 ). The second line of each test case consists of the initial string s ( 1 <= |s| <= 500 ). It is guaranteed, that s consists of the characters "1", "2", "3". It is guaranteed that the sum of x in a single file is at most 10^6 . It is guaranteed that in each test case before the procedure will stop it will be true that ell <= |s| at any time. For each test case, output a single line containing a single integer denoting the answer for that test case modulo 10^9 + 7 . Let 's illustrate what happens with the first test case. Initially, we have s = 231. Initially, ell = 0 and c = varepsilon (the empty string). The following things happen if we follow the procedure above: At th'...