// bài 1
#include<iostream>
using namespace std;

int main()
{
    cout << "Hello world" << endl;
    system("pause");
    return 0;
}
// bài 2
#include<iostream>
using namespace std;

int main()
{
    int x;
    int y;
    cout << "nhap x y";
    cin >> x >> y;
    if (x == 0)
    {
        if (y == 0)
        {
            cout << "tong 2 so  " << x + y << endl;
            cout << "hieu so   " << x - y << endl;
            cout << "tich 2 so  " << x*y << endl;
            cout << "khong co thuong  " << endl;
        }
        else
        {
            cout << "tong 2 so  " << x + y << endl;
            cout << "hieu x-y    " << x - y << endl;
            cout << "hieu so y-x   " << y - x << endl;
            cout << "tich 2 so  " << x*y << endl;
            cout << "thuong so x/y  " << x / y << endl;
        }

    }
    else
    {
        if (y == 0)
        {
            cout << "tong 2 so  " << x + y << endl;
            cout << "hieu so x-y   " << x - y << endl;
            cout << "hieu so y-x   " << y - x << endl;
            cout << "tich 2 so  " << x*y << endl;
            cout << "thuong so y/x  " << y / x << endl;

        }
        else
        {
            cout << "tong 2 so  " << x + y << endl;
            cout << "hieu so x-y  " << x - y << endl;
            cout << "hieu so y-x  " << y - x << endl;
            cout << "tich 2 so  " << x*y << endl;
            cout << "thuong so x/y  " << x / y << endl;
            cout << "thuong so y/x  " << y / x << endl;
        }
    }
    system("pause");
    return 0;
}
// bài 3
#include<iostream>
using namespace std;

int main()
{
    double dSothuc;
    cout << "nhap so thuc  ";
    cin >> dSothuc ;
    cout << static_cast<long long>(dSothuc) << endl;
    system("pause");
    return 0;
}
// bài 4
#include<iostream>
using namespace std;

int main()
{
    char a;
    cout << "nhap ki tu bat ky";
    cin >> a;
    cout << static_cast<int>(a) << endl;
    system("pause");
    return 0;
}
// bài 5
#include<iostream>
#include<ctime>
#pragma warning(disable:4996)
using namespace std;

int main()
{
    int nYear;
    cout << "nhap nam sinh";
    cin >> nYear;
    time_t baygio = time(0);
    tm*ltm = localtime(&baygio);
    cout << "so tuoi" << 1900 + ltm->tm_year - nYear << endl;
    system("pause");
    return 0;
}