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

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

int n,m,ans;
vector<int> g[100005];
bool viz[100005];

void dfs(int arg)
{
    for(int i=0; i<g[arg].size(); i++)
        if(!viz[g[arg][i]])
        {
            viz[g[arg][i]]=1;
            dfs(g[arg][i]);
        }
}
int main()
{
    int x,y;

    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }

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

    out<<ans<<'\n';
    return 0;
}