Create a block diagram

Вот сайт на котором нужно сделать https://app.diagrams.net/
А вот код
#include <iostream>

using namespace std;

int main()
{
int num;
cout << "How many numbers you will enter?"<<endl;
cin >> num;

int first_n,max_n;
cout << "First number:";
cin >> first_n;
max_n = first_n;

for (int i = 1; i < num; ++i) {
int num;
cout << "Write in next number: ";
cin >> num;

if (num > max_n) {
max_n = num;
}
}

int diff = max_n - first_n;
cout << "The difference is: " << diff;

return 0;
}