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 Rust (1.15.1) (judge verdict: Accepted)


use std::io;

fn main() {
    let mut ab = [0usize; 26usize];
    let mut line = String::new();
    io::stdin().read_line(&mut line);
    let mut line = line.trim();

    for c in line.bytes() {
        ab[(c - 97u8) as usize] += 1;
    }

    for i in 0..26 {
        if 1 < ab[i] {
            println!("no");
            return;
        }
    }

    println!("yes");
    return;
}