use proconio::input;
use std::collections::HashMap;

fn main() {
    input! {
        _n: usize,
        s: String,
    }

    let mut hash_map = HashMap::new();

    for c in s.chars() {
        *hash_map.entry(c).or_insert(0) += 1;
    }

    let ans = if hash_map.into_values().all(|v| v == 1) {
        "No"
    } else {
        "Yes"
    };

    println!("{ans}");
}