#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100000;
vector<int> v[N+1];
int n,m;
bool viz[N+1];

void DFS(int varf){
    viz[varf]= true;
    for(auto vecin: v[varf]){
        {
            if (!viz[vecin]) {
                DFS(vecin);
            }
        }
    }
}

int main() {
    in>>n>>m;
    int x,y;
    while(in>>x>>y) {
        v[x].push_back(y);
        v[y].push_back(x);
    }

    int cnt =0;
    for(int i=1;i<=n;i++){
        if(!viz[i]){
            DFS(i);
            cnt++;
        }
    }

    out<<cnt;
    return 0;
}