///Bai 1
#include <iostream>
using namespace std;
int main(){
    cout<<"Hello World";
    return 0;
}
///Bai 2
#include <iostream>
using namespace std;
int main(){
    int a,b;
    cout<<"nhap vao a:";
    cin>>a;
    cout<<"nhap vao b:";
    cin>>b;
    cout<<"tong="<<(a+b)<<endl;
    cout<<"hieu="<<(a-b)<<endl;
    cout<<"tich="<<(a*b)<<endl;
    cout<<"thuong="<<(a/b)<<endl;
    return 0;
}
///Bai 3
#include<iostream>
using namespace std;
int main(){
    float a;
    cout<<"nhap vao so thuc a=";
    cin>>a;
    int phannguyen;
    phannguyen=int(a);
    cout<<"phan nguyen =";
    cout<<phannguyen;
    return 0;
}
///Bai 4
#include<iostream>
using namespace std;
    int main(){
    char a;
    cout<<"nhap vao mot ky tu bat ki:";
    cin>>a;
    a=int(a);
    cout<<"ma ASCII la:"<<int(a)<<endl;
    return 0;
    }