Convert Sentence Problem Statement

Convert a given string 'S' into its equivalent representation based on a mobile numeric keypad sequence. Using the keypad layout shown in the reference, output the sequence of numbers that corresponds to typing 'S' on the keypad.

Input:

The first line contains an integer T, indicating the number of test cases.
The first line of each test case has an integer N, representing the length of the string 'S'.
The second line of each test case contains the string 'S'.

Output:

For each test case, output a single line with the numeric keypad sequence needed to type 'S'. Each test case's result is printed on a new line.

Example:

Input:

T = 1
N = 3
S = "abc"

Output:

"222"

Explanation:

If 'abc' is typed on the keypad, the output numeric sequence is '222'.

Constraints:

• 1 <= T <= 5
• 1 <= N <= 3000

Note:

No special characters, capital letters, or spaces will be present in the input string.
You do not need to implement I/O operations, just complete the given function.