#include<fstream>
#include<vector>
using namespace std;
int n, m, x, y, i, nr;
int viz[100002];
vector<int> v[100002];
ifstream fin("dfs.in");
ofstream fout("dfs.out");
void dfs(int x){
    viz[x] = 1;
    for(int i = 0; i < v[x].size(); i++){
        if(viz[v[x][i]] == 0){
            dfs(v[x][i]);
        }
    }
}
int main(){
    fin>> n >> m;
    for(i = 1; i <= m; i++){
        fin>> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i = 1; i <= n; i++){
        if(viz[i] == 0){
            nr++;
            dfs(i);
        }
    }
    fout<< nr <<"\n";
    return 0;
}