#include <fstream>
#include <vector>

using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
vector <int> v[100001];
bool viz[1000001];
int n, m, i, con, x, y;
void dfs(int x)
{
    int i;
    viz[x]=1;
    for(i=0;i<v[x].size();i++)
        if(viz[v[x][i]]==0)
            dfs(v[x][i]);
}
int main()
{
    fin >> n >> m;
    for(i=1;i<=m;i++)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0)
        {
            con++;
            dfs(i);
        }
    fout << con;
    return 0;
}