#include <bits/stdc++.h>
using namespace std;
#define mod                1000000007
#define ll                 long long 
#define all(v)             v.begin(), v.end()
#define fr(n)              for(ll i=0;i<n;++i)
#define ctz(x)             __builtin_ctzll(x)
#define clz(x)             __builtin_clzll(x)
#define pcount(x)          __builtin_popcountll(x)
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};
#define cin fin
#define cout fout
ifstream fin("dfs.in");
ofstream fout("dfs.out");
//const ll maxn = 3e5 + 5;
//int f[maxn],nf[maxn],inv[maxn];
//const int M=998244353;
//void init(){
//inv[1]=1; for (int i=2;i<maxn;i++) inv[i]=M-1ll*(M/i)*inv[M%i]%M;
//f[0]=nf[0]=1; for (int i=1;i<maxn;i++) f[i]=1ll*f[i-1]*i%M,nf[i]=1ll*nf[i-1]*inv[i]%M;
//}
//int C(int x,int y){return 1ll*f[x]*nf[y]%M*nf[x-y]%M;}

vector<ll> f(100001, 0);
vector< vector<ll> > v(100001);
void dfs(ll i){
    f[i]++;
    for(auto x:v[i]){
        if(!f[x]) dfs(x);
    }
}


void solve(){
    ll n, m;cin>>n>>m;
    fr(m){
        ll a,b;cin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    ll ans=0;
    for(ll i=1; i<=n; i++){
        if(!f[i]){
            dfs(i);
            ans++;
        }
    }
    cout<<ans;
    
    
}


int main(){
//    ios_base::sync_with_stdio(false); cin.tie(NULL);
//    ll t;cin>>t;while(t--){solve();cout<<endl;}
    solve();
}