#include <bits/stdc++.h>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> a[100001];

int viz[100001];

void DFS(int node)
{
    viz[node] = !viz[node];
    for (auto it : a[node])
    {
        if(!viz[node]) {
            DFS(node);
        }
        
    }
}
int main()
{
    int first_node, n, m;
    f>>n>>m;

    for (size_t i = 0; i < m; i++)
    {
        int x, y;
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);

    }

    int cnt = 0;
    for (size_t i = 1; i <= n; i++) {
        if (!viz[i]) {
            /* code */
            DFS(i);
            cnt++;
        }

    }

    g<<cnt;

    return 0;
}