#include <fstream>
#include <vector>
#define ios ios_base::sync_with_stdio(false);
#define Nmax 100005

using namespace std;

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

vector<int> g[Nmax];
int n,m,nr;
bool viz[Nmax];

void citire(){
    cin>>n>>m;
    for (int i=1;i<=m;i++){
        int x,y;
        cin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

void DFS(int ns){
    viz[ns]=1;
    for (unsigned j=0;j<g[ns].size();j++){
        if (viz[g[ns][j]]==0) {viz[g[ns][j]]=1; DFS(g[ns][j]);}
    }
}

int main()
{
    ios;
    cin.tie(0);
    cout.tie(0);
    citire();
    int i;
    for (i=1;i<=n;i++) if(viz[i]==0){nr++; DFS(i);}
    cout<<nr;
    return 0;
}