import sequtils, strutils

proc root(x: int, p: var seq[int]): int =
  if p[x] == -1: x
  else:
    p[x] = root(p[x], p)
    return p[x]

proc unite(x, y: int; p, rank, size: var seq[int]) =
  var
    rx = root(x, p)
    ry = root(y, p)
  if rank[rx] < rank[ry]: swap(rx, ry)
  p[ry] = rx
  if rank[rx] == rank[ry]: inc rank[rx]
  size[rx].inc size[ry]

var n, m: int
(n, m) = stdin.readLine.split.map parseInt
let ab = m.newSeqWith stdin.readLine.split.map parseInt

var
  p = (-1).repeat n * 2
  rank, size = 1.repeat n * 2

for v in ab:
  var
    a = pred v[0]
    b = pred v[1]
    ra = root(a, p)
    rb = root(b, p)
  if ra != rb: unite(a, b, p, rank, size)

var list: seq[int]
for i, v in p:
  if v == -1:
    list.add i

var cnt = 0
for idx in list:
  if size[idx] mod 2 == 1:
    inc cnt

echo cnt div 2