Task: Program Execution
Input (English): Sentence: 'a beautifully maintained park-like area with rolling green slopes  has lots of people, some far away among the trees, most in the small, windy roads to and from the trees, including two people with a buggy, some bike riders and lots of walkers'. Replace the letter 'y' with 'x' in the sentence.
Output (English): a beautifullx maintained park-like area with rolling green slopes  has lots of people, some far awax among the trees, most in the small, windx roads to and from the trees, including two people with a buggx, some bike riders and lots of walkers