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

const int N=100001;
bool viz[N];
int n,m,nc;

vector <int> a[N];

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

void dfs(int x)
{
    viz[x] = true;
    for(auto y:a[x])
    {
        if(!viz[y])
        {
            dfs(y);
        }
    }
}

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);
    }
    for(int i=1; i <= n; i++)
    {
        if(!viz[i])
        {
            nc++;
            dfs(i);
        }
    }
    out << nc;
    in.close();
    out.close();
    return 0;
}