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: Accepted)

#include <stdio.h>
int main(void)
{
    char s[25];
    for(int p=0;p<26;p++)
    {
        scanf("%s",&s[p]);
    }
    int q=0;
    while(s[q] !=NULL)
      q++;
    int x=0;
    for(int r=0;r<q-1;r++)
    {
        for(int t=r+1;t<q;t++)
        {
            if(s[r]==s[t])
            {
                x++;
            }
        }
    }
    if(x==0)
      printf("yes");
    else
      printf("no");
}