#define NMAX 100005
#include <fstream>
#include <vector>
using namespace std;

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

int n, m, viz[NMAX];
vector<int> graph[NMAX];

void read()
{
    int x, y;

    f>>n>>m;
    for(int i = 0; i < m; ++i)
    {
        f>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
}

void dfs(int nod)
{
    viz[nod] = 1;
    for(auto &v:graph[nod])
        if(viz[v] == 0)
            dfs(v);
}



int main()
{
    read();

    int nr = 0;
    for(int i = 1; i <= n; ++ i)
        if(viz[i] == 0)
        {
            dfs(i);
            nr++;
        }
    g<<nr;
    return 0;
}