#include <fstream>
#include <vector>

using namespace std;

int viz[100002];
vector <int> g[100002];

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

int main()
{
    int n, m, x, y, i, k = 0;

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

    fin >> n >> m;

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

    for(i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            dfs(i);
            k++;
        }
    }

    fout << k;
    return 0;
}