#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, viz[100005], sol;
vector <int> a[100005];
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()
{
    int i, j, x, y;
    fin >> n >> m;
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (i = 1; i <= n; i++)
        if (viz[i] == 0)
        {
            Dfs(i);
            sol++;
        }
    fout << sol << "\n";




    return 0;
}