#include <fstream>
#include <vector>
 
using namespace std;
vector<vector<int>> G;
vector<bool> seen;
 
void dfs(int nod)
{
    seen[nod] = true;
    for (vector<int>::iterator it = G[nod].begin(); it != G[nod].end(); it++)
    {
        if (!seen[*it])
        {
            dfs(*it);
        }
    }
}
 
int main()
{
    vector<vector<int>> G;
    vector<bool> seen;
    int N, M, i, j, x, y;
    ifstream f("dfs.in");
    f >> N >> M;
    G.resize(N + 1);
    seen.resize(N + 1, 0);
    for (i = 1; i <= M; i++)
    {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
 
    int num = 0;
    for (int i = 1; i <= N; i++)
    {
        if (!seen[i])
        {
            dfs(i);
            num++;
        }
    }
 
    ofstream g("dfs.out");
    g << num;
    g.close();
 
    return 0;
}