Letters Only

Check if the given string consists of only letters and spaces and if every letter is in lower case.

Examples

lettersOnly("JAVACRIPT") ➞ false

lettersOnly("javascript") ➞ true

lettersOnly("12321313") ➞ false

lettersOnly("i have spaces") ➞ true

lettersOnly("i have numbers(1-10)") ➞ false

lettersOnly("") ➞ false

Notes

• Empty arguments will always return false.
• Input values will be mixed (symbols, letters, numbers).