s = "abcdabab"
print s.find("ab")
print s.find("ab", 5)
print s.index("ab")
print s.index("ab", 5)
print s.find("ac")
print s.find("ac", 5)

print s.rfind("cd")
print s.rfind("cd", 5)
print s.rindex("ab")
print s.rindex("ab", 5)
print s.rfind("ac")
print s.rfind("ac", 5)
print s.rindex("ac", 5)