#include <fstream>
#include <vector>
#define Nmax 100001

using namespace std;

vector <int> G[Nmax];
int n,m,conex;
bool v[Nmax];

ifstream f("dfs.in");
ofstream g("dfs.out");
void ReadGraph()
{
    int x, y;
    f>>n>>m;

    while (f>>x>>y)
    {
        G[x].push_back(y);
        G[y].push_back(x);
    }


}
void DFS(int x)
{
    v[x]=true;
    for(size_t i=0;i<G[x].size();++i)
    {
        int y=G[x][i];
        if(v[y])
            continue;
        DFS(y);
    }

}
int main()
{

    ReadGraph();
    for(int p=1;p<=n;p++)
        if(v[p]==0)DFS(p),conex++;
    g<<conex;

}