import sys
import email

if len(sys.argv) < 2:
    print("Usage: python3 extract_email_headers.py <email_file>")
    sys.exit(1)

file_path = sys.argv[1]
with open(file_path, 'rb') as f:
    msg = email.message_from_bytes(f.read())

from_addr = msg.get('From', '')
to_addrs = msg.get_all('To', []) + msg.get_all('Cc', [])
recipients = ','.join([str(addr) for addr in to_addrs]) if to_addrs else ''

print(f'FROM:{from_addr}')
print(f'RECIPIENTS:{recipients}')