#include <bits/stdc++.h>
#include<fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out")
const int NMAX=1e5;
vector<int> L[NMAX+1];

int vs[NMAX+1];

void dfs(int node){
    vs[node]=1;
    for(auto vec:L[node]){
        if (vs[vec]==0){
            dfs(vec);
        }
    }
}

int main() {
	int n,m;
    fin>>n>>m;
    for(int i=1;i<=m;++i){
        int x,y;
        cin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int cc=0;
    for(int i=1;i<=n;++i){
        if(vs[i]==0){
            cc++;
            dfs(i);

        }
    }
    fout<<cc;
    fin.close();
    fout.close();
}