#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

const int NMAX = 1e5;
vector < int > L[NMAX + 1];
int viz[NMAX + 1];

void DFS(int x)
{
    viz[x] = 1;
    for(auto next : L[x])
    {
        if(viz[next] == 0)
        {
            DFS(next);
        }
    }
}

int main()
{
    int n, m, cc = 0;
    f>>n>>m;
    for(int i = 1; i <=m; i++)
    {
        int x, y;
        f>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            cc++;
            DFS(i);
        }
    }
    g<<cc;
    return 0;
}