#include <fstream>
#include <vector>
using namespace std;
const int NMAX=100000;
vector <int> G[NMAX+5];
int viz[NMAX+5];
void dfs(int u,int cc)
{
    int v,j;
    viz[u]=cc;
    for(j=0;j<G[u].size();j++)
    {
        v=G[u][j];
        if(!viz[v])
            dfs(v,cc);
    }
}
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int main()
{
    int n,m,u,v,i,cc;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>u>>v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
    cc=0;
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            cc++;
            dfs(i,cc);
        }
    }
    fout<<cc;
    return 0;
}