fname = raw_input('Enter the file name: ')
try:
fhand = open(fname)
except:
print 'File cannot be opened:', fname
exit()
count = 0
total = 0
for line in fhand:
words = line.split()
if len(words) != 2 : continue
if words[0] != 'X-DSPAM-Confidence:' : continue
try:
conf = float(words[1])
except:
continue
count = count + 1
total = total + conf
average = total / count
print 'Average spam confidence:', average