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

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m, cnt;
vector<int> G[100001];
bool V[100001];

void Dfs(int x)
{
    V[x] = true;
    for (int y : G[x])
    {
        if (!V[y])
            Dfs(y);
    }
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= m; ++i)
    {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i)
    {
        if (!V[i])
        {
            ++cnt;
            Dfs(i);
        }
    }
    fout << cnt;

    return 0;
}