add and commit.

Signed-off-by: zhujk <zhujk.icode@gmail.com>
print another message.

Signed-off-by: zhujk <zhujk.icode@gmail.com>
Revert "print another message."

This reverts commit e31539a4f608804db594c3bfe9e80d4551ae160c.
add add method.
add mul method.
add sub method.
add div method.
add DemoC class.
print aaa.
add Demo class.
print hahahahaha.
add DDD class.
print haa.
Merge branch 'master' into ccc
add Master class.
add CCC class.
add BBB class.
add CCCCC class.
Merge commit '0dc76f743ebf245becef76dd40b1fde4d32b95d6' into bbb
add BBBBB class.