#include<fstream>
#include<algorithm>
#include<vector>
#define a first.first
#define b first.second
#define c second

using namespace std;
vector <int> v[100003];
vector <int> :: iterator it;
int n, m2, m[100003], x, y, z, i, sol;;
ifstream in("dfs.in");
ofstream out("dfs.out");
void dfs(int nod){
    m[nod]=1;
    for(int i=0; i<v[nod].size(); i++){
        int fiu=v[nod][i];
        if(m[fiu]==0){
            dfs(fiu);
        }
    }
}
int main(){
    in>>n>>m2;
    for(i=1; i<=m2; i++){
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1; i<=n; i++){
        if(m[i]==0){
            dfs(i);
            sol++;
        }
    }
    out<<sol;
    return 0;
}