#include <fstream>
#include <vector>
#include <bitset>
using namespace std;

#define maxd 100010

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

int n, m, x, y, nr;
vector <int> a[maxd];
bitset <maxd> viz;

void dfs(int c){
    viz[c]=true;
    for(int i=0;i<a[c].size();++i){
        int g=a[c][i];
        if(!viz[g]) dfs(g);
    }
}


int main(){
    fin>>n>>m;
    for(;m;--m){
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i]) nr++, dfs(i);
    fout<<nr;

    return 0;
}