#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<vector>
#include<queue>
#include<bitset>
#include<string>
#include<stack>
#include<set>
#include<unordered_set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<complex>
#include<cmath>
#include<iomanip>
#include<numeric>
#include<algorithm>
#include<list>
#include<functional>
#include<cassert>
#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define y0 y12
#define y1 y22
#define INF 987654321
#define PI 3.141592653589793238462643383279502884
#define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
#define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
#define MEM0(a) memset((a),0,sizeof(a));
#define MEM_1(a) memset((a),-1,sizeof(a));
#define ALL(a) a.begin(),a.end()
#define SYNC ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;
typedef pair<ld, ld> Pd;
typedef vector<int> Vi;
typedef vector<ll> Vll;
typedef vector<double> Vd;
typedef vector<Pi> VPi;
typedef vector<Pll> VPll;
typedef vector<Pd> VPd;
typedef tuple<int, int, int> iii;
typedef tuple<int,int,int,int> iiii;
typedef tuple<ll, ll, ll> LLL;
typedef vector<iii> Viii;
typedef vector<LLL> VLLL;
typedef complex<double> base;
const ll MOD = 1000000007;
ll POW(ll a, ll b, ll MMM = MOD) {ll ret=1; for(;b;b>>=1,a=(a*a)%MMM)if(b&1)ret=(ret*a)% MMM; return ret; }
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { if (a == 0 || b == 0)return a + b; return a*(b / gcd(a, b)); }
int dx[] = { 0,1,0,-1,1,1,-1,-1 }, dy[] = { 1,0,-1,0,1,-1,1,-1 };
int n,m,k;
VPi v[100001];
int ee[200001],ev[100001],oe[200001],ov[100001];
int depth[100001],num[100001],c;
void dfs(int N,int p, int d)
{
num[N]=++c;
depth[N]=d;
for(auto P:v[N])
{
if(P.Y==p || num[P.X]>num[N])continue;
if(num[P.X])
{
if((depth[N]-depth[P.X]) &1)
{
ee[P.Y]++;
ev[N]++,ev[P.X]--;
}
else
{
oe[P.Y]++;
ov[N]++,ov[P.X]--,k++;
}
}
else
{
dfs(P.X,P.Y,d+1);
ov[N]+=ov[P.X];
ev[N]+=ev[P.X];
}
}
oe[p]+=ov[N],ee[p]+=ev[N];
}
int main() {
scanf("%d%d",&n,&m);
fup(i,1,m,1)
{
int x,y;
scanf("%d%d",&x,&y);
v[x].pb(mp(y,i));
v[y].pb(mp(x,i));
}
fup(i,1,n,1)if(!num[i])dfs(i,0,1);
int ans=0;
fup(i,1,m,1)if(oe[i]==k && ee[i]==0)ans++;
printf("%d",ans);
}
