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

using namespace std;
int n, m, nr;
bool viz[100001];
vector<int> graf[100001];

void dfs(int k)
{
    viz[k] = 1;
    for(int i = 0; i < graf[k].size(); i++)
    {
        int vecin = graf[k][i];
        if(viz[vecin] == 0)
            dfs(vecin);
    }
}

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

    int x, y;
    cin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        cin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        if(viz[i] == 0)
        {
            nr++;
            dfs(i);
        }

    cout << nr;

    return 0;
}