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 OCaml (4.10.0) (judge verdict: Accepted)

open Base
open Stdio

let () =
  match In_channel.input_line In_channel.stdin with
  | None -> failwith "cannot read input"
  | Some k -> let k = Int.of_string k in
    match In_channel.input_line In_channel.stdin with
    | None -> failwith "cannot read input"
    | Some x -> let length = String.length x in
      if length <= k
      then print_endline x
      else print_endline ((String.sub x ~pos:0 ~len:k) ^ "...")