import math, sequtils, strformat, strutils, sugar


proc parseTuple(x: string): (int64, float64) =
  if '.' notin x:
    return (x.parseInt, 0.0)
  let
    idx = x.find '.'
    a = parseInt x[0..(idx-1)]
    b = parseFloat "0." & x[idx+1..^1]
  if x[0] != '-':
    return (a, b)
  else:
    return (a, -b)


let
  n = parseInt stdin.readLine
  seq1 = newSeq.collect:
    for _ in 0 ..< n:
      parseTuple stdin.readLine
  ans1 = sum seq1.mapIt it[0]
  ans2 = sum seq1.mapIt it[1]
var
  (a, b) = parseTuple &"{ans2:.12f}"
a += ans1

if (a > 0) and (b < 0):
  b = 1.0 + b
  a -= 1
if (a < 0) and (b > 0):
  b = 1.0 - b
  a += 1

stdout.write a
echo (&"{b:.10f}")[1..^1]