3540
He said , when one hacker would leave a ransom note , another hacker would target the same database , delete the original ransom note and leave their own .
 ( ransom: would leave,  one hacker: attacker, a ransom note: tool) 
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: would leave,  one hacker: attacker, a ransom note: tool) 