#include <fstream>
#define dim 100005
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,i,m,sol,f[dim],x,y;
vector <int>v[dim];
void dfs(int x){
    f[x]=1;
    for(int i = 0; i<v[x].size();i++){
        if(f[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(f[i]==0){
            sol++;
            dfs(i);
        }
    }
    fout<<sol<<"\n";



    return 0;
}