#change the first character occurence in a string to "$", except the first character itself

my_str = input("Enter the string: ")
print((my_str.replace(my_str[0], "$")).replace("$", my_str[0], 1))
86e286b264daae5b06ca4eb995de4702c1eb8da2
<mask token>

<mask token>
print(my_str.replace(my_str[0], '$').replace('$', my_str[0], 1))

my_str = input('Enter the string: ')
print(my_str.replace(my_str[0], '$').replace('$', my_str[0], 1))

#change the first character occurence in a string to "$", except the first character itself

my_str = input("Enter the string: ")
print((my_str.replace(my_str[0], "$")).replace("$", my_str[0], 1))