5167
One officer and one soldier of Israeli army were killed in an exchange of fire with Palestinian militants near the border between  Israel  and the southern Gaza Strip Friday afternoon  Israel Defense Forces  ( IDF ) confirmed in a statement .
 country of headquarters: Israel, Israel Defense Forces
Given a phrase that describes the relationship between two words, extract the words and the lexical relationship between them. The output format should be "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
Answer:
 country of headquarters: Israel, Israel Defense Forces