#include<fstream>
#include<vector>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int>v[100001];
int nr,n,viz[100001],m;
void df(int i)
{
    viz[i]=1;
    for(int j=0;j<v[i].size();j++)
    if(!viz[v[i][j]])
        df(v[i][j]);
}
int main()
{
    int x,y;
    f>>n>>m;
    while(f>>x>>y){v[x].push_back(y);v[y].push_back(x);}
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nr++;
            df(i);
        }
    }
    g<<nr<<'\n';


    return 0;
}