#include <fstream>
#include <vector>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n,m,a,b,cnt;
vector<vector<int>> v(100005);
vector<bool> f(100005);

void dfs(int node){
    f[node]=1;
    for(auto i:v[node]){
        if(!f[i]){
            dfs(i);
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        fin>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(int i=1;i<=n;i++){
        if(!f[i]){
            cnt++;
            dfs(i);
        }
    }
    fout<<cnt;
    return 0;
}