#include <fstream>
#include <vector>

using namespace std;

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

const int N=1e5+1;

int n,m;
vector<int> a[N];
bool viz[N];

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

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int cnt=0;
    for(int i=1; i<=n; i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            cnt++;
        }
    }
    out<<cnt;
    return 0;
}