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_macros)]
macro_rules! parse_line {
    [$( $x:tt : $t:ty ),+] => {
        //declare variables
        $( let $x: $t; )+
        {
            use std::str::FromStr;
            // read
            let mut buf = String::new();
            std::io::stdin().read_line(&mut buf).unwrap();
            #[allow(deprecated)]
            let mut splits = buf.trim_right().split_whitespace();
            // assign each variable
            $(
                $x = splits.next().and_then(|s| <$t>::from_str(s).ok()).unwrap();
            )+
            // all strs should be used for assignment
            assert!(splits.next().is_none());
        }
    };
}

fn main() {
    parse_line![len: usize];
    parse_line![s: String];

    if s.len() <= len {
        println!("{}", s);
    } else {
        println!("{}...", &s[..len]);
    }
}