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>
#include <string.h>
 

int main(void) {
  
  int i, j;
  int tmp =0;
  
  char str[26];
  
  scanf("%s", str);
  
  for(i = 0; i < strlen(str); i++) {
     for(j = i + 1; j < strlen(str); j++) {
     
     if(str[i] == str[j]) {
     
     tmp = 1;
  }
  
  }
  
  }
  
  if (tmp == 1) {
    printf("no\n");
    
  } else {
    printf("yes\n");
    
  }
  
    return 0;
  }