code for making result of your subject by C++

the code is 

#include<iostream>

using namespace std;

void main()

{

int a;

int b;

int c;

int d;

int e;

int f;

int total=240;

cout << "please enter your marks" << endl;

cout << "math=" << endl;

cin >> a;

cout << "english=" << endl;

cin >> b;

cout << "physics=" << endl;

cin >> c;

cout << "biology=" << endl;

cin >> d;

cout << "chemistry=" << endl;

cin >> e;

cout << "urdu=" << endl;

cin >> f;

cout << "your total marks=" << a + b + c + d + e + f << endl;

cout << "percentage%=" << (a + b + c + d + e + f) * 100 / total << endl;

}

thank you guys .