#include <fstream>
#include <vector>

using namespace std;

#define NMAX 100005

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

int N,M,Count;
bool Used[NMAX];
vector<int> G[NMAX];

void Read(){
    f>>N>>M;
    int x,y;
    for (int i = 1; i <= M; ++i) {
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int Node){
    Used[Node] = true;
    for (vector<int>::iterator it = G[Node].begin(); it != G[Node].end(); it++ ) {
        if (!Used[*it]) {
            DFS(*it);
        }
    }
}

void Solve(){
    for (int i = 1; i<= N; i++) {
        if (!Used[i]) {
            DFS(i);
            Count++;
        }
    }
}

void Write(){
    g<<Count;
}

int main() {

    Read();
    Solve();
    Write();
    
    return 0;
}