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>
using namespace std;
int main(void){
    // Your code here!
    string s;
    cin >> s;
    int n = s.length();
    int map[256] = {};
    int flag = 0;
    for(int i = 0; i < n; i++){
        if(map[s[i]] == 1)flag = 1;
        map[s[i]] = 1;
    }
    cout << (flag == 0 ? "yes" : "no");
}