import math, sequtils, strformat, strutils, sugar


proc parseTuple(x: string): (int, float64) =
  if '.' notin x:
    return (parseInt x, 0.0)
  let
    idx = x.find '.'
    a = parseInt x[..(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]
  (a, b) = parseTuple $ans2

stdout.write ans1 + a
echo (&"{b:.10f}")[1..^1]