#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int NMAX=100000;
vector <int> G[NMAX+5];
bitset <100000>viz;
int n, m;
int DFS(int x)
{
    int i;
    viz[x]=1;
    for(i=0;i<G[x].size();i++)
        if(viz[G[x][i]]==0)
        DFS(G[x][i]);
}
int main()
{
    int nrc=0, x, y, i;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nrc++;
            DFS(i);
        }
    }
    fout<<nrc<<"\n";
    return 0;
}