Typeracer game (incomplete)

#include "pch.h"
#include <iostream>
#include <thread>
#include <windows.h>
#include <string>

using namespace std;

//Typeracer game
double timer = 0;
bool end_game = false;

void hellothere()
{
    while (!end_game)
    {
        if (timer == 30)
        {
            end_game = true;
            system("cls");
        }
        Sleep(1000);
        timer++;
    }
}

char word[5];
string input_from_player;

void intitialize_word()
{
    srand(time(NULL));
    for (int x = 0; x < 5; x++)
    {
        word[x] = (rand() % 25) + 97;
    }
    input_from_player = word;
}

int main()
{
    intitialize_word();

    double points = 0;

    thread clock(hellothere);

    while (!end_game)
    {
        for (int k = 0; k < 5; k++)
        {
            cout << word[k];
        }

        cout << endl;

        cin >> input_from_player;
        if (input_from_player == word)
        {
            intitialize_word();
            points++;
        }
        system("cls");

        if (points == 10)
        {
            end_game = true;
        }
    }

    clock.join(); //End time

    double words_per_minute = (points/timer) * 60;

    cout << words_per_minute << endl;

    cout << "You typed 10 words over a period of " << timer << " seconds" << endl;
    cout << "This estimates to " << words_per_minute << " words per minute." << endl;

    int pause; cin >> pause; //Pause the game
}