#include <fstream>
#include <vector>
#define nmax 100005
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,nr,i,x,y;
bool u[nmax];
vector <int> v[nmax];
void dfs(int k)
{
    int i; u[k]=1;
    for (i=0; i<v[k].size(); ++i)
        if (u[v[k][i]]==0)
            dfs(v[k][i]);
}
int main()
{
    f>>n>>m;
    for (i=0; i<m; ++i)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i=1; i<n+1; ++i)
        if (u[i]==0)
        {
            dfs(i);
            ++nr;
        }
     g<<nr<<'\n';
     return 0;
}