#include <iostream>
#include <fstream>
#include <vector>

int mark[100001];
std::vector<std::vector<int>> v(100001);
void dfs(int nod)
{
    mark[nod] = 1;
    for (auto &&i : v[nod])
    {
        if (mark[i]==0)
        {
            dfs(i);
        }
        
    }
}
int main()
{
    std::ifstream cin("dfs.in");
    std::ofstream cin("dfs.out");
    int n, m, a,b,compConex = 0;
    cin >> n >> m;

    for (size_t i = 0; i < m; i++)
    {
        cin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (size_t i = 0; i < n; i++)
    {
        if (mark[i] == 0)
        {
            dfs(i);
            compConex++;
        }
    }
    cout << compConex << '\n';
}