/**
- @param words String
- @return String
*/
var Solution = function(words){
var a=words.length var b=parseInt(a/2) var count=0 for(var i=0;i<b;i++) { if(words[i]===words[a-1-i]) { count=count+1 } } if(count===b) { return '???' }else { return '????' }
}
