s = 'hello world'

print(len(s))

print(s.upper())

print(s.lower())

print(s.capitalize())

print(s.title())

print(s.swapcase())

print(s.startswith('hello'))

print(s.endswith('world'))

print(s.find('o'))

print(s.rfind('o'))

print(s.index('e'))

print(s.replace('world', 'python'))

print(s.split())

print('-'.join(['a', 'b', 'c']))