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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<iostream>
#include<float.h>
#include<cfloat>
#include<string>
#include<ctype.h>
#include<algorithm>
#include<errno.h>
#include<cerrno>
#include<assert.h>
#include<cassert> 
#include<map>
#include<memory.h>
#include<cctype>
#include<ctype.h>
#include<math.h>
#include<vector> 
#include<cstdio> 
#include<set>
#include<string.h>
#include<stdio.h>
#include<new>
#include<memory>
#include<cmath>
#include<queue>
#include<cstring>
#define ll long long
#define fo(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define br break
#define ct continue
#define pb push_back
#define pi 3.141592653589793238462643383279502884197169
#define F first
#define S second
#define em empty()
#define vei vector<int>
#define ves vector<string>
#define qui queue<int> 
#define qu queue
using namespace std;
int main()
{string s;
 cin>>s;
 fo(i,0,s.size())
 fo(j,i,s.size())
 if(s[i]!=s[j]){
 cout<<"no"<<endl;
 }
 cout<<"yes"<<endl;
 return 0;
}