#include <fstream>
#include <vector>

using namespace std;


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

const int N=100001;


vector <int> a[N];

bool viz[N];


void dfs(int x)
{
    int i, y;
    viz[x]=true;
    for(i=0;i<a[x].size();i++)
    {
        y=a[x][i];
        if(!viz[y]) dfs(y);
    }
}


int main()
{
    int n,m,x,y,i,nr;

    in>>n>>m;

    for(i=1;i<=m;i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    nr=0;
    for(i=1;i<=n;i++)
        if(!viz[i]){
            nr++;
            dfs(i);

        }

    out<<nr;

    return 0;
}