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>
using namespace std;
int main() {
	int check=0;
	string a;
	cin >> a;
	for (int i = 0; i < a.size()-1; i++) {
		for (int j = i+1; j < a.size(); j++) {
			if (a[j] == a[i]) {
				check++;
			}
		}
	}
	if (check == 0)
		cout << "Yes";
	else
		cout << "No";
	return 0;
}