#!/usr/bin/python
import sys
import argparse
import time
import datetime

argparser = argparse.ArgumentParser()
argparser.add_argument('--verbose', '-v', action='store_true')
argparser.add_argument('--alpha', '-a', type=float, default=0.1)
args = argparser.parse_args()

if args.alpha < 0.0 or args.alpha > 1.0:
    raise ValueError, "you suck"

ewma = 0.0
def update(weight):
    global ewma
    ewma = args.alpha*weight + (1.0 - args.alpha)*ewma

last_ordinal = None
last_weight = None
for ln in sys.stdin:
    date, weight = ln.split()
    date = datetime.datetime.strptime(date, '%Y-%m-%d')
    weight = float(weight)
    ordinal = date.toordinal()

    if args.verbose:
        print (date.toordinal(), weight)

    if last_ordinal is None:
        last_ordinal = ordinal
        last_weight = weight
        ewma = weight
    else:
        last_ordinal += 1
        while last_ordinal < ordinal:
            if args.verbose:
                print 'Missing day, using', last_weight
            update(last_weight)
            last_ordinal += 1

    if args.verbose:
            print 'Update with', weight
    update(weight)
    last_weight = weight

    print date.strftime('%Y-%m-%d'), ewma