#include <iostream>using namespace std;#include <stdlib.h>void f1(){cout<<"call f1()"<<endl;}void f2(){cout<<"call f2()"<<endl;}int main(){	atexit(f1);	atexit(f2);	cout << "input an integer:";	int n;	cin >> n;	cout << "n*n=" << n*n << endl;	return 0;	cout << "you can't see me!" << endl;}