6450
I found the following report that was presented to Congress recently about the shoulder launched missle threat to airliners , which this might very well be a precursor to : Recent events have focused attention on the threat that terrorists with shoulder fired surface - to - air missiles ( SAMs ) , referred to as Man - Portable Air Defense Systems ( MANPADS ) , pose to commercial airliners .
 Congress, I, terrorists with shoulder fired surface - to - air missiles ( SAMs ) , referred to as Man - Portable Air Defense Systems ( MANPADS, airliners, commercial airliners, the shoulder launched missle, shoulder fired surface - to - air missiles, SAMs, Man - Portable Air Defense Systems, MANPADS
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: organization, person, geographical social political, vehicle, location, weapon, facility 
Text: {0} 
Answer:
 Congress, I, terrorists with shoulder fired surface - to - air missiles ( SAMs ) , referred to as Man - Portable Air Defense Systems ( MANPADS, airliners, commercial airliners, the shoulder launched missle, shoulder fired surface - to - air missiles, SAMs, Man - Portable Air Defense Systems, MANPADS