i. a
ii. a
iii. a
iv. a
v. a
vi. a
vii. a
viii. a
ix. a
x. a
xi. a
xii. a
xiii. a
xiv. a
xv. a
xvi. a
xvii. a
xviii. a
xix. a
xx. a
xxi. a
xxii. a
xxx. a
xl. a
xliii. a
l. a
lx. a
lxix. a
xc. a
c. a

it breaks down at c, but maybe that's enough...

ci. a
cx. a
cxl. a
cl. a
cxc. a
cc. a
ccc. a
cd. a
d. a
cm. a
m. a