
    Write a function that modifies a bus route identifier by removing both the first and last instance of a specific route designation character to standardize route naming conventions across the transit system. The function should take a complete bus route identifier string and a specific route designation character as inputs, and return the modified route identifier with both occurrences of the designation character removed.
    

    
def remove_Occ(s, ch):
    """
    Write a function that modifies a bus route identifier by removing both the first and last instance of a specific route designation character to standardize route naming conventions across the transit system. The function should take a complete bus route identifier string and a specific route designation character as inputs, and return the modified route identifier with both occurrences of the designation character removed.
    

    """
def remove_Occ(s, ch):
    """
    Write a function that modifies a bus route identifier by removing both the first and last instance of a specific route designation character to standardize route naming conventions across the transit system. The function should take a complete bus route identifier string and a specific route designation character as inputs, and return the modified route identifier with both occurrences of the designation character removed.
    

    """
    for i in range(len(s)):
        if s[i] == ch:
            s = s[0:i] + s[i + 1:]
            break
    for i in range(len(s) - 1, -1, -1):
        if s[i] == ch:
            s = s[0:i] + s[i + 1:]
            break
    return s