my_string = 'Hello world'
print(my_string[0])
print(my_string[-11])

print(my_string[6:11])

my_string_2 = 'abababab'
print(my_string_2[::2])

my_string_3 = 'abcabcabcabc'
print(my_string_3[::3])

# [start:stop:step]
my_string_4 = '12345678'
print(my_string_4[1:8:2])
# reverse
print(my_string_4[::-1])



