#include<fstream>
#include<vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> L[100005];
int v[100005];
int n,m,a,b,q1,i,j,k,sol;
int maxim;
void dfs(int nod){
    v[nod]=1;
    for(int i=0;i<L[nod].size();i++){
        int fiu=L[nod][i];
        if(v[fiu]==0){
            dfs(fiu);
        }
    }
}
int main(){
    fin>>n>>m;
    for(i=1;i<=m;i++){
        fin>>a>>b;
        L[a].push_back(b);
        L[b].push_back(a);
    }
    for(i=1;i<=n;i++){
        if(v[i]==0){
            dfs(i);
            sol++;
        }
    }
    fout<<sol;
    return 0;
}