Extract the first string element

Return the first letter of the given string.

Sample Code:

function firstLetter(str) {
// Enter your logic here...
}

Examples:

Input: 'Codetisan'
Output: 'C'
Explanation: 'C' element has an index value of 0.

Input: ' Javascript'
Output: ' '
Explanation: ' ' element has an index value of 0.