Fill visual area

Just have fun!

Input

vim: set nrformats=alpha:
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Output

vim: set nrformats=alpha:
jihgfedcba
iihgfedcba
hhhgfedcba
ggggfedcba
fffffedcba
eeeeeedcba
dddddddcba
ccccccccba
bbbbbbbbba
aaaaaaaaaa