#include <vector>
#include <fstream>

using namespace std;

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

vector <int> v[100005];
bool viz[100005];
int m,n,x,y,nr;

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0; i<v[nod].size(); i++)
        if(!viz[v[x][i]])
            dfs(v[x][i]);
}

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            dfs(i);
            nr++;
        }
    out<<nr;
    return 0;
}