#include <fstream>
#include <vector>
using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

const int nmax=200002;
vector<vector<int>>adj(nmax);
int viz[nmax];

void dfs(int node)
{
    for(int next:adj[node])
    {
        if(viz[next]==0)
        {
            viz[next]=1;
            dfs(next);
        }
    }
}

int main()
{
    int n,m,i,c=0;
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        int u,v;
        cin>>u>>v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            c++;
            dfs(i);
        }
    }
    cout<<c;
    return 0;
}