Language: C++

import std.stdio;
import std.array;
import std.conv;
import std.algorithm;
import std.range;
import std.string;
import std.typecons;


alias Tuple!(int, string) P;

void main()
{
  for(int n; (n = to!int(chomp(readln()))) != 0; ){
    int[string] hash;

    foreach(i; 0..n){
      foreach(word; split(chomp(readln()))){
        hash[word]++;
      }
    }

    char k = to!char(chomp(readln()));
    P array[];

    foreach(word, count ; hash){
      if(word[0] == k){
    	array ~= tuple(count, word);
      }
    }

    sort!((P a, P b){ return a[1] < b[1] || (a[1] == b[1] && a[0] > b[0]); })(array\
);

    bool flag =	true;
    int	up = min(cast(int)array.length, 5);
    foreach(i; 0..up){
      writef("%s%c", array[i][1], (i + 1 == up ? '\n' : ' '));
      flag = false;
    }

    if(flag) writeln("NA");
  }
}

int min(int a, int b)
{ return a > b ? b : a; }

Compiler output:
a.cc:17:16: error: too many decimal points in number
   17 |     foreach(i; 0..n){
      |                ^~~~
a.cc:37:16: error: too many decimal points in number
   37 |     foreach(i; 0..up){
      |                ^~~~~
a.cc:1:1: error: 'import' does not name a type
    1 | import std.stdio;
      | ^~~~~~
a.cc:1:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:2:1: error: 'import' does not name a type
    2 | import std.array;
      | ^~~~~~
a.cc:2:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:3:1: error: 'import' does not name a type
    3 | import std.conv;
      | ^~~~~~
a.cc:3:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:4:1: error: 'import' does not name a type
    4 | import std.algorithm;
      | ^~~~~~
a.cc:4:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:5:1: error: 'import' does not name a type
    5 | import std.range;
      | ^~~~~~
a.cc:5:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:6:1: error: 'import' does not name a type
    6 | import std.string;
      | ^~~~~~
a.cc:6:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:7:1: error: 'import' does not name a type
    7 | import std.typecons;
      | ^~~~~~
a.cc:7:1: note: C++20 'import' only available with '-fmodules-ts'
a.cc:10:1: error: 'alias' does not name a type
   10 | alias Tuple!(int, string) P;
      | ^~~~~
a.cc:12:1: error: '::main' must return 'int'
   12 | void main()
      | ^~~~
a.cc: In function 'int main()':
a.cc:14:19: error: 'to' was not declared in this scope
   14 |   for(int n; (n = to!int(chomp(readln()))) != 0; ){
      |                   ^~
a.cc:14:21: error: expected ')' before '!' token
   14 |   for(int n; (n = to!int(chomp(readln()))) != 0; ){
      |              ~      ^
      |                     )
a.cc:15:8: error: structured binding declaration cannot have type 'int'
   15 |     int[string] hash;
      |        ^~~~~~~~
a.cc:15:8: note: type must be cv-qualified 'auto' or reference to cv-qualified 'auto'
a.cc:15:17: error: expected initializer before 'hash'
   15 |     int[string] hash;
      |                 ^~~~
a.cc:15:17: error: expected ';' before 'hash'
a.cc:17:13: error: 'i' was not declared in this scope
   17 |     foreach(i; 0..n){
      |             ^
a.cc:24:5: error: 'P' was not declared in this scope
   24 |     P array[];
      |     ^
a.cc:26:13: error: 'word' was not declared in this scope
   26 |     foreach(word, count ; hash){
      |             ^~~~
a.cc:26:19: error: 'count' was not declared in this scope
   26 |     foreach(word, count ; hash){
      |                   ^~~~~
a.cc:26:27: error: 'hash' was not declared in this scope
   26 |     foreach(word, count ; hash){
      |                           ^~~~
a.cc:32:5: error: 'sort' was not declared in this scope; did you mean 'short'?
   32 |     sort!((P a, P b){ return a[1] < b[1] || (a[1] == b[1] && a[0] > b[0]); })(array\
      |     ^~~~
      |     short
a.cc:32:77: error: expected primary-expression before ')' token
   32 |     sort!((P a, P b){ return a[1] < b[1] || (a[1] == b[1] && a[0] > b[0]); })(array\
      |                                                                             ^
a.cc:36:23: error: expected primary-expression before 'int'
   36 |     int up = min(cast(int)array.length, 5);
      |                       ^~~
a.cc:36:18: error: 'cast' was not declared in this scope
   36 |     int up = min(cast(int)array.length, 5);
      |                  ^~~~
a.cc:36:14: error: 'min' was not declared in this scope; did you mean 'main'?
   36 |     int up = min(cast(int)array.length, 5);
      |              ^~~
      |              main
a.cc:37:14: error: expected ')' before ';' token
   37 |     foreach(i; 0..up){
      |            ~ ^
      |              )
a.cc:42:14: error: 'writeln' was not declared in this scope
   42 |     if(flag) writeln("NA");
      |              ^~~~~~~