#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define sz size()
#define x first
#define y second
#define pi pair <int, int>
#define pii pair <pi, pi>
#define vi vector <int>
vi g[100001];
const ll mod = 1e9 + 7;
int ans, n, m, x, y, viz[100001];

void dfs(int nod){
    viz[nod]=1;
    for(int i=0; i<g[nod].sz; i++){
        if(!viz[g[nod][i]]) dfs(g[nod][i]);
    }
}

int32_t main(){
    ios_base :: sync_with_stdio(0); cin.tie(); cout.tie();
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    cin>>n>>m;
    for(int i=1; i<=m; i++){
        cin>>x>>y;
        g[x].pb(y);
        g[y].pb(x);
    }
    for(int i=1; i<=n; i++){
        if(!viz[i]) dfs(i); ans++;
    }
    cout<<ans;
}