Can anyone solve this in C++ without using a main function

I know it has to use some sort of string erase function but I cant figure it out

When comparing sentences we are often not interested in differences in case (UPPERCASE vs lowercase) or punctuation. For this problem, you will be writing a function that takes two string parameters- sentence and punctuation and returns the same string in lowercase remember the built-in tolower function) and with given punctuation removed. You must use nested loops. The built lowerNoPunctuation returns a string and takes a two strings as parameters: string lowerNoPunctuation(string str, string punch) //Your code here Example Output: string str "Hello, my name is Inigo Montoya, You killed my father, Prepare to die!" string punct = "!?". string newStr = lowerNPunctuation (str, punct) cout