Fax McClad, Croneria's most scientific bounty hunter, is funding research for more efficient fuel.
There are ~26~ different types of fuel molecules, labelled from
z. Two fuel molecules of different types can react to become energy, annihilating the molecules. Thus, a fuel molecule can be a part of at most one reaction.
Fax's scientists have just received a batch of fuel molecules represented by a string ~S~. Is it possible to react all fuel molecules?
The first line of input will contain a single integer, ~|S|~ ~(1 \le |S| \le 10^5)~, the length of ~S~.
The second line of input will contain ~S~, a string containing only characters
z, representing fuel molecule types.
Yes if all molecules can be reacted, output
Sample Input 1
Sample Output 1
Sample Input 2
Sample Output 2