#include<bits/stdc++.h>
using namespace std;

string numeFisier="dfs";
ifstream fin(numeFisier+".in"); ofstream fout(numeFisier+".out");
#define cin fin
#define cout fout

#define INIT  ios_base :: sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define mp make_pair
#define pb push_back
#define ft first
#define sc second
#define ll long long
#define pii pair<int, int>
#define count_bits __builtin_popcount
//#define int ll


int n, m;
vector<int> g[100010];
bool v[100010];


void dfs(int s){
v[s]=true;
for(int u:g[s]){
    if(!v[u]){
        dfs(u);
    }
}

}

int32_t main(){
INIT
cin>>n>>m;
for(int i=1; i<=m; i++){
    int u,v;
    cin>>u>>v;
    g[u].pb(v); g[v].pb(u);
}

int cnt=0;
for(int i=1; i<=n; i++){
    if(!v[i]){
        cnt++;
        dfs(i);
    }
}
cout<<cnt;

return 0;
}