#include <fstream>
#include <vector>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
const int N=100010;
int n,m,c,viz[N];
vector<int> v[N];
void dfs(int nod)
{
    viz[nod]=1;
    for(auto vecin:v[nod])
        if(!viz[vecin])
            dfs(vecin);
}
int main()
{
    f>>n>>m;
    for(;m;m--)
    {
        int x,y;
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
        c++;
        dfs(i);
    }
    g<<c;
    return 0;
}