// parcurgere dfs
#include <fstream>
#include <vector>

#define nmax 1000010
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");


int n, m, counter;
vector<int> adj[nmax];
bool visited[nmax];

void dfs(int node){
    visited[node] = true;
    for(auto it = adj[node].begin(); it != adj[node].end(); it++)
        if(!visited[*it]) dfs(*it);
}

int main() {
    f >> n >> m;
    while(m--) {
        int a,b;
        f >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    for(int i = 1; i <= n; i++) {
        if(!visited[i]) {dfs(i); counter++;}
    }

    g << counter;
}