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In Nayana 's first announcement a few days later , it said the hackers demanded 550 bitcoins to free up all the servers -- about $ 1.62 million .
 ( ransom: demanded,  the hackers: attacker, 550 bitcoins: price, the servers: victim, $ 1.62 million: price) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: phishing, data breach, ransom, discover vulnerability, patch vulnerability, Arguments type: vulnerable system, capabilities, vulnerability, number of victim, issues addressed, compromised data, damage amount, common vulnerabilities and exposures, victim, patch number, number of data, tool, discoverer, time, purpose, place, payment method, releaser, vulnerable system version, attacker, supported platform, patch, price, vulnerable system owner, trusted entity, attack pattern. 
Text: {0} 
Answer:
 ( ransom: demanded,  the hackers: attacker, 550 bitcoins: price, the servers: victim, $ 1.62 million: price) 