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)
{
	int C = 0;
	int i,j;
	char S[26];
	scanf("%26s",S);
	for( i = 0; i < sizeof(S) / sizeof(S[0]); i++){
	for( j = 0; j < sizeof(S) / sizeof(S[0]); j++){
		if( S[i] == S[j] ) C++ ;
	}
	}
	if( C == sizeof(S) / sizeof(S[0]) ) printf("yes");
	else printf("no");
	return 0;
}