#include <vector>
#include <fstream>
using namespace std;

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

int n, m, x, y, rez;
bool viz[100005];
vector < int > mat[100005];

void dfs(int nod){
    viz[nod] = 1;
    for(unsigned i=1;i<=mat[nod].size();i++){
        int vec = mat[nod][i];
        if(viz[vec]==0){
            dfs(vec);
        }
    }
}

int main(){
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        fin>>x>>y;
        mat[x].push_back(y);
        mat[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(viz[i]==0){
            rez++;
            dfs(i);
        }
    }
    fout<<rez;
    return 0;
}