#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 1e5 + 5;
int n, m, cnt;
int dep[N];
array<int, 2> a[N];
bool vis[N];
vector<int> g[N];
void dfs(int u, int p) {
vis[u] = 1;
bool flg = 0;
for (int v : g[u]) {
if (v == p && !flg) {
flg = 1;
continue;
}
if (!vis[v]) {
dep[v] = dep[u] + 1;
dfs(v, u);
} else if (dep[u] > dep[v]) {
int c = (dep[u] - dep[v] - 1) & 1;
++a[u][c];
--a[v][c];
cnt += c;
}
}
}
void DFS(int u) {
vis[u] = 1;
for (int v : g[u]) {
if (!vis[v]) {
DFS(v);
for (auto j : {0, 1}) {
a[u][j] += a[v][j];
}
}
}
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n >> m;
while (m--) {
int u, v; cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
for (int i = 1; i <= n; ++i) {
if (!vis[i]) {
dfs(i, i);
}
}
memset(vis, 0, sizeof(vis));
for (int i = 1; i <= n; ++i) {
if (!vis[i]) {
DFS(i);
}
}
int res = 0;
for (int i = 1; i <= n; ++i) {
res += dep[i] && a[i][1] == cnt && !a[i][0];
}
res += cnt == 1;
cout << res;
return 0;
}
