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)

#![allow(unused_imports)]
#![allow(non_snake_case)]
use std::collections::HashMap;
use std::collections::HashSet;
use std::collections::VecDeque;

#[allow(unused_macros)]
macro_rules! read {
    ([$t:ty] ; $n:expr) =>
        ((0..$n).map(|_| read!([$t])).collect::<Vec<_>>());
    ($($t:ty),+ ; $n:expr) =>
        ((0..$n).map(|_| read!($($t),+)).collect::<Vec<_>>());
    ([$t:ty]) =>
        (rl().split_whitespace().map(|w| w.parse().unwrap()).collect::<Vec<$t>>());
    ($t:ty) =>
        (rl().parse::<$t>().unwrap());
    ($($t:ty),*) => {{
        let buf = rl();
        let mut w = buf.split_whitespace();
        ($(w.next().unwrap().parse::<$t>().unwrap()),*)
    }};
}

#[allow(dead_code)]
fn rl() -> String {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).unwrap();
    buf.trim_end().to_owned()
}

fn main() {
    let k = read!(usize);
    let s = read!(String);
    if s.len() <= k {
        println!("{}", s);
    } else {
        println!("{}...", &s[0..k]);
    }
}