#include <fstream>
#include <vector>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int nmax=100000;
vector <int> g[nmax+1];
int viz[nmax+1];
void fill(int k){
    int i,y;
    viz[k]=1;
    for(i=0;i<g[k].size();++i){
        y=g[k][i];
        if(!viz[y]){
            fill(y);
        }
    }
}
int main()
{
    int n,m,i,nr=0,x,y;
    fin>>n>>m;
    for(i=0;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]){
            ++nr;
            fill(i);
        }
    }
    fout<<nr;

    return 0;
}