#include <fstream>
#include <vector>

using namespace std;

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

int n,m,i,j,x,nr,y;
bool viz[100010];

vector<int> l[100010];
void DFS(int nod)
{
    viz[nod]=1;

    for(int i=0;i<l[nod].size();++i)
    {
        if(viz[ l[nod][i] ]==0)
        {
            DFS(l[nod][i]);
        }
    }
}

int main()
{
    fin>>n>>m;
    for(i=1;i<=m;++i)
    {
        fin>>x>>y;
        l[x].push_back(y);
        l[y].push_back(x);
    }

    for(i=1;i<=n;++i)
    {
        if(viz[i]==0)
        {
            DFS(i);
            ++nr;
        }
    }
    fout<<nr;

    return 0;
}