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>
int main(void){
char s[100];
  int count,flag=0;
  scanf("%s",&s);
  for(count=0;s[count]=='\0';count++){
  if(s[count]==s[count+1]){}  
    else{flag=1; break;}
  }
  if(flag==1){printf("no\n");}
  else{printf("yes\n");}
return 0;
}