Make All Same

The chef is fond of playing games and excels in them by winning. Today chef has found a game in which he has to convert any binary string into a palindromic string. The game has certain rules. In one operation, Chef will choose different indices i, j and then do one of the following - replace **arr[ i ]** with xor of **arr[ i ]** and **arr[ j ]** - or replace **arr[ j ]** with xor of **arr[ i ]*