ARROWS DETECTION IN C++

Question

I tried to make a simple program to detect the arrows (up, down, right, and left) like shown in my code:

#include <iostream>
#include <conio.h>
#define up 72
#define down 80
#define right 77
#define left 75

using namespace std;
 

int main(){
    int n = 0;

    for (int i = 0 ; i < 4 ; ++i){
        n = getch();
        if (n == 72) cout << "UP\n";
        else if (n == 80) cout << "DOWN\n";
        else if (n == 77) cout << "RIGHT\n";
        else if (n == 75) cout << "LEFT\n"; 
        else cout << "NO\n";    
    }

            
return 0;
}

So it is supposed that the loop will iterate 4 times but it actually iterates 2 times and this what is given to me when I press the up key 2 times :

So what should I do and thanks in advance