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 9.2.1) (judge verdict: Accepted)

#include<stdio.h>
int main(void)
{
    char s[27];
    int i=0,a[10000]={0},b=0;
    scanf("%s",s);
    while(s[i]!='\0'){
        a[s[i]]++;
        if(a[s[i]]==2){
            b++;
            break;
        }
        i++;
    }
    if(b==1)
        printf("no\n");
    else 
        printf("yes\n");
    return 0;
}