#include <fstream>
#include <vector>
#define DIM 100001
using namespace std;
ifstream fi("dfs.in");
ofstream fo("dfs.out");
int n,m;
int x,y;
vector<int> V[DIM];
int VIZ[DIM];
int rez;
void dfs(int v)
{
    VIZ[v]=1;
    for(int i=0;i<V[v].size();i++)
        if(VIZ[V[v][i]]==0)
            dfs(V[v][i]);
}
int main()
{
    fi>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fi>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(VIZ[i]==0)
        {
            dfs(i);
            rez++;
        }
    fo<<rez;
    fi.close();
    fo.close();
    return 0;
}