#include <fstream>
#include <vector>

#define NMAX 100000

using namespace std;

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

int viz[NMAX],n,m,x,y,cc;
vector <int> v[NMAX];

void DFS(int x)
{
    int y;
    viz[x]=1;
    for(unsigned int i=0;i<v[x].size();i++)
    {
        y=v[x][i];
        if(viz[y]==0)
            DFS(y);
    }
}

int main()
{
    int i;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            cc++;
            DFS(i);
        }
    }
    g<<cc;
}