import re
p = re.compile(r'( of (?:(?!\band\b)[A-Za-z ])+)?')
s = " of New Mexico and Mrs Smith."
m = p.search(s)
if m:
print(m.group().strip())
aW1wb3J0IHJlCnAgPSByZS5jb21waWxlKHInKCBvZiAoPzooPyFcYmFuZFxiKVtBLVphLXogXSkrKT8nKQpzID0gIiBvZiBOZXcgTWV4aWNvIGFuZCBNcnMgU21pdGguIgptID0gcC5zZWFyY2gocykKaWYgbToKCXByaW50KG0uZ3JvdXAoKS5zdHJpcCgpKQ==