#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<int> g[100001];
bool f[100001];
void dfs(int nod)
{
    f[nod] = true;
    for(int i = 0; i < g[nod].size(); i++)
    {
        if(f[g[nod][i]] == false)
        {
            dfs(g[nod][i]);
        }
    }
    return;
}
int main()
{
    int n, m;
    cin >> n >> m;
    for(int i = 0; i < m; i++)
    {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int cnt = 0;
    for(int i = 1; i <= n; i++)
    {
        if(f[i] == false)
        {
            dfs(i);
            cnt++;
        }
    }
    cout << cnt;
}