The best location is in front of the front of the old man's tombstone, because in customs and habits, it is said that "the back is the top".
However, due to geographical or conditional restrictions, if you can only choose the left and right rows, according to the orientation of the old man's tombstone, the children should choose the right side of the old man's tombstone. The old man's tombstone should always be arranged on the left, because according to custom It is customary to say "left is up".