#include <fstream>
#include <vector>

using namespace std;

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

int i,j,m,n,x,y,nr;
vector <int> GGWP[100005];
bool ok[100005];

void dfs(int x)
{
    vector <int>::iterator it;
    ok[x]=true;
    for(it=GGWP[x].begin(); it!=GGWP[x].end(); it++)
    {
        if(ok[*it]==false) dfs(*it);
    }
}
int main()
{
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x>>y;
        GGWP[x].push_back(y);
        GGWP[y].push_back(x);

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