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

ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m;
bool ok[100001];
vector<int> v[100001];

void dfs(int i){
    for(unsigned j=0;j<v[i].size();j++)
        if(!ok[v[i][j]]){
            ok[v[i][j]]=1;
            dfs(v[i][j]);
        }
    return;
}

int main()
{
    f>>n>>m;

    for(int i=1;i<=m;i++){
        int a,b;
        f>>a>>b;
        v[b].push_back(a);
        v[a].push_back(b);
    }
    int s=0;
    for(int i=1;i<=n;i++)
        if(!ok[i]){
            s++;
            ok[i]=1;
            dfs(i);
        }
    g<<s;
    return 0;
}