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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<limits.h>

int main(void){
    char S[30];
    scanf("%s", S);
    int i;
    int hist['z'+1] = {0};
    for(i=0; i<=strlen(S)-1; i++) {
        if(hist[S[i]] > 0) {
            printf("No\n");
            return 0;
        }
        else {
            hist[S[i]]++;
        }
    }
    printf("Yes\n");
    return 0;
}