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

int viz[100001], n, m;
vector <int> graf[100005];

void dfs(int x)
{
    viz[x] = 1;
    int dim = graf[x].size();
    for(int i = 0; i <= dim - 1; i++)
    {
        int vecin = graf[x][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}
int main()
{
    int i, j;
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin>>n>>m;
    for(i = 1; i <= m; i++)
    {
        int x, y;
        fin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    int k = 0;
    for(i = 1; i <= n; i++)
        if(!viz[i])
        {
            dfs(i);
            k++;
        }
    fout<<k;
    return 0;
}