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: Accepted)

#include<iostream>
#include<map>
using namespace std;
map<char, int> s;
int main()
{
	string s1;
	while(cin>>s1)
	{
		int flag = 0;
		for(int i = 0; i < s1.size(); i++)
		{
			if(s.count(s1[i]) == 1)
			{
				flag  = 1; 
				cout<<"no"<<endl;
				break;
			}
			else
				s[s1[i]] = 0;
		}
		if(flag)
			continue;
		cout<<"yes"<<endl;
	}
	return 0;
}