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#! /usr/bin/env python

import sys

last_key = None
count = 0
sum = 1

# keys come grouped together
# so we need to keep track of state a little bit
# thus when the key changes , we need to reset
# our counter, and write out the count we've accumulated

for line in sys.stdin:
   line = line.strip()
   key, value = line.split("\t")

   # we have to be able to deal with missing values
   if value =="NA":
       continue

   value = int(value)

   # if this is the first iteration
   if not last_key:
       last_key = key
       count = 1
       sum = value + 0.0

    # if they're the same, log it
   elif key == last_key:
        count = count + 1
        sum = sum + value

   else:
        result = [last_key, sum/count]
        print("\t".join(str(v) for v in result))
        last_key = key
        count = 1
        sum = value

# this is to catch the final value that we output
print("\t".join(str(v) for v in [last_key, sum/count]))