Revert "To show some problems and solutions"

This reverts commit 3c1e380f9bc412d513936b0d02cd27d1aa711341.
Revert "Revert "To show some problems and solutions""

This reverts commit 4bbe0347f9e3e1cb8294aae52cd8f72500c0b69a.
Revert "To show some problems and solutions"

This reverts commit 3c1e380f9bc412d513936b0d02cd27d1aa711341.
to show problems and solutions