#include <fstream>
#include <vector>

using namespace std;

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

const int nmax = 100005;
int n, viz[nmax];
vector<int> vecin[nmax];

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

int main()
{
    int m, x, y;
    int ans = 0;
    f >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        f >> x >> y;
        vecin[x].push_back(y);
        vecin[y].push_back(x);
    }
    
    for (int i = 1; i <= n; i++)
    {
        if (!viz[i])
        {
            dfs(i);
            ans++;
        }
    }
    
    g << ans;
    
    return 0;
}