#pragma warning(disable:4996)
#include<stdio.h>
#include<algorithm>
#include<vector>
using namespace std;
struct A{
int a, b;
}tp;
vector<A>E[100010];
int n, m, Dep[100010], par[100010], S, D[100010], Res, ord[100010], cnt;
bool v[100010], chk[200010];
void DFS(int a)
{
ord[++cnt] = a;
int i;
Dep[a] = Dep[par[a]] + 1;
v[a] = true;
for (i = 0; i < E[a].size(); i++){
if (!v[E[a][i].a]){
chk[E[a][i].b] = true;
par[E[a][i].a] = a;
DFS(E[a][i].a);
}
}
}
int main()
{
int i, a, b, j, ck;
scanf("%d%d", &n, &m);
for (i = 1; i <= m; i++){
scanf("%d%d", &a, &b);
tp.a = b, tp.b = i;
E[a].push_back(tp);
tp.a = a;
E[b].push_back(tp);
}
for (i = 1; i <= n; i++){
if (!v[i]){
DFS(i);
}
}
for (i = 1; i <= n; i++){
for (j = 0; j < E[i].size(); j++){
if (!chk[E[i][j].b]){
chk[E[i][j].b] = true;
ck = -1;
if ((Dep[i] + Dep[E[i][j].a]) % 2 == 0){
S++;
ck = 1;
}
a = E[i][j].a, b = i;
if (Dep[i] > Dep[E[i][j].a])swap(a, b);
D[a] += ck, D[b] += -ck;
}
}
}
if (S == 1)Res++;
for (i = cnt; i >= 1; i--){
a = ord[i];
D[par[a]] += D[a];
if (D[a] == S && par[a]){
Res++;
}
}
printf("%d\n", Res);
}
