Consider the following tree for a prefix code:

A tree with $5$ vertices. The top vertex branches into character, a$,$ on the left, and a vertex on the right. The vertex in the second level branches into character, e$,$ on the left, and a vertex on the right. The vertex in the third level branches into two vertices. The left vertex in the fourth level branches into character, c$,$ on the left, and character, n$,$ on the right. The right vertex in the fourth level branches into character, d$,$ on the left, and character, y$,$ on the right. The weight of each edge branching left from a vertex is $0.$ The weight of each edge branching right from a vertex is $1.$