#include <string>
#include <exception>
#include <vector>
#include <iostream>

using namespace std;

class account {
	string nm;
	long bal; // balance is in pennies (or smaller)

public:
	// account(string n) : nm(n), bal(0) {}
	account(string n, long initial_bal = 0) :
		nm(n), bal(initial_bal) {
                   // check the invariant!
                   if (nm == "" || bal < 0)
                   	throw runtime_error("account(): invalid parameters");
	}

	string name() const { return nm; }
	long balance() const { return bal; }

	long deposit(long amount) { // can also do withdraw
		// check the invariant!
		account tmp(nm, bal+amount);
		bal = tmp.bal;
		return bal;
	}

	long withdraw(long amount) {
		return deposit(-amount); // re-use code, don't copy-paste!!!
	}
};