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

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

int n, m, c;
vector <int> G[100005];
bool Use[100005];

void DFS(int nod)
{
    Use[nod] = 1;
    for(int i = 0; i < (int)G[nod].size(); i++)
    {
        int vecin = G[nod][i];
        if(!Use[vecin]) DFS(vecin);
    }
}

int main()
{
    f>>n>>m;
    while(m--)
    {
        int x, y;
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(!Use[i])
        {
            DFS(i);
            c++;
        }
    }
    g<<c<<'\n';
    return 0;
}