Please tell me how to do it.contract EthUsdPriceTicker is usingOraclize

[chitokiser]

The examples in the book do not compile because they are not interactive.
Please tell me how to do it.

Using Oraclize to update the ETH/USD exchange rate from an external source

//MIT License

/*
ETH/USD price ticker leveraging CryptoCompare API

This contract keeps in storage an updated ETH/USD price,
which is updated every 10 minutes.
*/

pragma solidity ^0.4.1;

import "https://github.com/provable-things/ethereum-api/blob/master/oraclizeAPI_0.5.sol";

/*
"oraclize_" prepended methods indicate inheritance from "usingOraclize"
*/
contract EthUsdPriceTicker is usingOraclize {

uint public ethUsd;

event newOraclizeQuery(string description);
event newCallbackResult(string result);

function EthUsdPriceTicker() payable {
    // signals TLSN proof generation and storage on IPFS
    oraclize_setProof(proofType_TLSNotary | proofStorage_IPFS);

    // requests query
    queryTicker();
}

function __callback(bytes32 _queryId, string _result, bytes _proof) public {
    if (msg.sender != oraclize_cbAddress()) throw;
    newCallbackResult(_result);

    /*
     * Parse the result string into an unsigned integer for on-chain use.
     * Uses inherited "parseInt" helper from "usingOraclize", allowing for
     * a string result such as "123.45" to be converted to uint 12345.
     */
    ethUsd = parseInt(_result, 2);

    // called from callback since we're polling the price
    queryTicker();
}

function queryTicker() external payable {
    if (oraclize_getPrice("URL") > this.balance) {
        newOraclizeQuery("Oraclize query was NOT sent, please add some ETH to cover for the query fee");
    } else {
        newOraclizeQuery("Oraclize query was sent, standing by for the answer...");

        // query params are (delay in seconds, datasource type,
        // datasource argument)
        // specifies JSONPath, to fetch specific portion of JSON API result
        oraclize_query(60 * 10, "URL","json(https://min-api.cryptocompare.com/data/price?\fsym=ETH&tsyms=USD,EUR,GBP).USD");
    }
}

}