#include <fstream>
#include <vector>

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

int n,m,counter;
vector<int> V[100002];

bool viz[100002];

void dfs(int start)
{
    for(int nod = 0;nod<V[start].size();nod++)
    {
        if(!viz[V[start][nod]])
        {
            viz[V[start][nod]]=true;
            dfs(V[start][nod]);
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=0;i<m;i++)
    {
        int x,y;
        fin>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i);
            counter++;
        }
    fout<<counter;
    return 0;
}