Problem:
Score: 200 points

Problem Statement

We have a string S consisting of lowercase English letters.

If the length of S is at most K, print S without change.

If the length of S exceeds K, extract the first K characters in S, append ... to the end of them, and print the result.

Constraints

K is an integer between 1 and 100 (inclusive).

S is a string consisting of lowercase English letters.

The length of S is between 1 and 100 (inclusive).

Input

Input is given from Standard Input in the following format:

K
S

Output

Print a string as stated in Problem Statement.

Sample Input 1

7
nikoandsolstice

Sample Output 1

nikoand...

nikoandsolstice has a length of 15, which exceeds K=7.

We should extract the first 7 characters in this string, append ... to the end of them, and print the result nikoand....

Sample Input 2

40
ferelibenterhominesidquodvoluntcredunt

Sample Output 2

ferelibenterhominesidquodvoluntcredunt

The famous quote from Gaius Julius Caesar.

Solution in Rust (1.42.0) (judge verdict: Accepted)

use std::cmp::*;
use std::io::*;
use std::str::FromStr;
//portable utility
#[allow(dead_code)]
fn switch<T>(flag: bool, true_value: T, false_value: T) -> T {
    if flag {
        true_value
    } else {
        false_value
    }
}
#[allow(dead_code)]
fn read<T: FromStr>() -> T {
    let stdin = stdin();
    let stdin = stdin.lock();
    let token: String = stdin
        .bytes()
        .map(|c| c.expect("failed to read char") as char)
        .skip_while(|c| c.is_whitespace())
        .take_while(|c| !c.is_whitespace())
        .collect();
    token.parse().ok().expect("failed to parse token")
}
#[allow(dead_code)]
fn read_string() -> Vec<char> {
    read::<String>().chars().collect()
}
#[allow(dead_code)]
fn read_vector<T: FromStr>(number: usize) -> Vec<T> {
    (0..number).map(|_| read()).collect()
}

fn main() {
    let k: usize = read();
    let s: String = read();
    if s.len() <= k {
        println!("{}", s);
    } else {
        let ss: String = s.chars().take(k).collect();
        println!("{}...", ss);
    }
}