library SafeMath {
function mul(uint256 a, uint256 b) internal constant returns (uint256) {
uint256 c = a * b;
assert(a == 0 || c / a == b);
return c;
}

function div(uint256 a, uint256 b) internal constant returns (uint256) {
assert(b > 0); // Solidity automatically throws when dividing by 0
uint256 c = a / b;
assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}

function sub(uint256 a, uint256 b) internal constant returns (uint256) {
assert(b <= a);
return a - b;
}

function add(uint256 a, uint256 b) internal constant returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}

// ERC20 Token Smart Contract
contract RealStateToken {

string public constant name = "RealStateToken";
string public constant symbol = "RSTI";
uint8 public constant decimals = 0;
uint public _totalSupply = 1000000000;
uint256 public RATE = 1;
bool public isMinting = true;
string public constant generatedBy = "Togen.io by Proof Suite";

using SafeMath for uint256;
address public owner;

// Functions with this modifier can only be executed by the owner
modifier onlyOwner() {
if (msg.sender != owner) {
throw;
}
_;
}

// Balances for each account
mapping(address => uint256) balances;
// Owner of account approves the transfer of an amount to another account
mapping(address => mapping(address=>uint256)) allowed;

// Its a payable function works as a token factory.
function () payable{
createTokens();
}

// Constructor
constructor() public {
owner = 0xe926cb75757f0d4af5c579ac89001290677c2e03; 
balances[owner] = _totalSupply;
}

//allows owner to burn tokens that are not sold in a crowdsale
function burnTokens(uint256 _value) onlyOwner {

require(balances[msg.sender] >= _value && _value > 0 );
_totalSupply = _totalSupply.sub(_value);
balances[msg.sender] = balances[msg.sender].sub(_value);

}



// This function creates Tokens 
function createTokens() payable {
if(isMinting == true){
require(msg.value > 0);
uint256 tokens = msg.value.div(100000000000000).mul(RATE);
balances[msg.sender] = balances[msg.sender].add(tokens);
_totalSupply = _totalSupply.add(tokens);
owner.transfer(msg.value);
}
else{
throw;
}
}


function endCrowdsale() onlyOwner {
isMinting = false;
}

function changeCrowdsaleRate(uint256 _value) onlyOwner {
RATE = _value;
}



function totalSupply() constant returns(uint256){
return _totalSupply;
}
// What is the balance of a particular account?
function balanceOf(address _owner) constant returns(uint256){
return balances[_owner];
}

// Transfer the balance from owner's account to another account 
function transfer(address _to, uint256 _value) returns(bool) {
require(balances[msg.sender] >= _value && _value > 0 );
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
Transfer(msg.sender, _to, _value);
return true;
}

// Send _value amount of tokens from address _from to address _to
// The transferFrom method is used for a withdraw workflow, allowing contracts to send
// tokens on your behalf, for example to "deposit" to a contract address and/or to charge
// fees in sub-currencies; the command should fail unless the _from account has
// deliberately authorized the sender of the message via some mechanism; we propose
// these standardized APIs for approval:
function transferFrom(address _from, address _to, uint256 _value) returns(bool) {
require(allowed[_from][msg.sender] >= _value && balances[_from] >= _value && _value > 0);
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
Transfer(_from, _to, _value);
return true;
}

// Allow _spender to withdraw from your account, multiple times, up to the _value amount.
// If this function is called again it overwrites the current allowance with _value.
function approve(address _spender, uint256 _value) returns(bool){
allowed[msg.sender][_spender] = _value; 
Approval(msg.sender, _spender, _value);
return true;
}

// Returns the amount which _spender is still allowed to withdraw from _owner
function allowance(address _owner, address _spender) constant returns(uint256){
return allowed[_owner][_spender];
}

event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}