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 <bits/stdc++.h>

using namespace std;

int main() {
    int count = 0;
    string s;
    cin >> s;
    for (int i = 0; i < s.size(); i++) {
        for (int j = 0; j < s.size(); j++) {
            if (s[i] == s[j]) {
                count++;
            }
        }
        if (count >= 2) break;
        count = 0;
    }

    if (count >= 2)cout << "no" << endl;
    else cout << "yes" << endl;

    return 0;
}