#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100001;
vector<int> a[N];
int n, m, nr=0;
int viz[N];

void citire()
{
    int i, x, y;
    in>>n>>m;
    for(i = 0; i < m; i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    in.close();
}

//parcurg vecinii lui x

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

int main()
{
    citire();
    for (int i=1;i<=n;i++)
        if (!viz[i])
        {
            dfs(i);
            nr++;
        }
    out<<nr;
}