#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int> L[100005];
bool vis[100005];

void dfs(int nod) {
    vis[nod] = 1;
    for (int i=0;i<L[nod].size();i++) {
        int vecin = L[nod][i];
        if (!vis[vecin]) {
            dfs(vecin);
        }
    }
}

int main(){
    int n,m;
    fin>>n>>m;
    for (int i=1;i<=m;i++) {
        int x,y;
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int cc=0;
    for (int i=1;i<=n;i++) {
        if(vis[i]) continue;
        cc++;
        dfs(i);
    }
    fout<<cc<<endl;
    return 0;
}