#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int N=100001;
vector<int>H[N];
bitset<N>uz;
void dfs(int x)
{
    uz[x]=1;
    for(vector<int>::iterator it=H[x].begin();it!=H[x].end();it++)
    {
        if(uz[*it]==0) dfs(*it);
    }
}
int main()
{
    int n,m,i,a,b;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        H[a].push_back(b);
        H[b].push_back(a);
    }
    int nr=0;
    for(i=1;i<=n;i++)
    {
        if(uz[i]==0) nr++,dfs(i);
    }
    fout<<nr;
}