Problem:
Score : 200 points

Problem Statement

You are given a string S consisting of lowercase English letters. Determine whether all the characters in S are different.

Constraints

2 ≤ |S| ≤ 26, where |S| denotes the length of S.

S consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

S

Output

If all the characters in S are different, print yes (case-sensitive); otherwise, print no.

Sample Input 1

uncopyrightable

Sample Output 1

yes

Sample Input 2

different

Sample Output 2

no

Sample Input 3

no

Sample Output 3

yes

Solution in JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

process.stdin.resume();
process.stdin.setEncoding('utf8');
// Here your code !
process.stdin.on('data', function (chunk) {
    var lines = chunk.toString().split(' ');
    var L = parseInt(lines[0].length);
    var str = chunk.toString().split("");
    var ans = 0;
    
    for(i = 0; i<L; i++){
        if(str[i+1] == str[i]){
            ans = ans +1 ;
        
        }else{
            ans =0 ;
        }    
    }
    
    
        /*if(ans=0){
     console.log("yes");
       }else{
     console.log("no");
           
       }*/
    
    
    if(ans>0){
     console.log("no");
       }else{
     console.log("yes");
           
       }
   
});