import sys
if len(sys.argv) <> 3:
print "Usage: " + sys.argv[0] + "file1 file2"
sys.exit(-1)
file1 = sys.argv[1]
file2 = sys.argv[2]
list1 = {}
for line in open(file1):
list1[line.split()[0]] = 1
for line in open(file2):
key = line.split()[0]
if key not in list1:
sys.stdout.write(line)
