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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <string>
using namespace std;

int main(void){
    string s;
    cin >> s;
    int count = 0;

    for(int i = 0; i < s.length()-1; i++){
        for(int j = i+1; j < s.length(); j++){
            if(s[i] == s[j])
                count++;
        }
    }
    if(count == 0)
        cout << "yes" << endl;
    else
        cout << "no" << endl;
    
    return 0;
}