#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100001;
int n,m,s,nr;
vector <int> g[N];
int v[N];

void citire()
{
    int x,y;
    for(int i = 1; i <= m; i++)
    {
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

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

int main()
{
    cin >> n >> m;
    citire();
    for(int i = 1; i <= n; i++)
        if(!v[i])
        {
            dfs(i);
            nr++;
        }
    cout << nr;
    return 0;
}