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){
char text[50];
 char t[64]; 
int len;
int flag=0;
int i;
scanf("%s",text);
len =strlen(text);
strcpy(t,text);
for(i=0;i<len;i++){
int j=0;
while(text[j]!='\0' && t[i]!='\0'){
    if(text[j]==t[i]&&(i!=j)){
      flag=1;
      break;
}
j++;
}
}
if(flag==1)
    printf("no");
  else
    printf("yes");

return 0;
}