#include <fstream>
#include <vector>

using namespace std;

vector <int> g[100005];
int use[100005];
int n,m,sol;

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

void read()
{
    int x,y;
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

void dfs(int nod)
{
    use[nod]=1;
    for(unsigned int i=0; i<g[nod].size(); i++)
    {
        int vecin=g[nod][i];
        if(use[vecin]==0) dfs(vecin);
    }
}


int main()
{
    read();

    for(int i=1;i<=n;i++)
        if(use[i]==0)
        {
            sol++;
            dfs(i);
        }
    out<<sol<<'\n';
    return 0;
}