#include <fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,x,y,i,j,cnt;
vector < int > v[100005];
bool viz[100005];
void dfs(int nod)
{
    int i;
    viz[nod]=1;
    for(i=0;i<v[nod].size();i++)
        if (viz[v[nod][i]] == 0)
            dfs(v[nod][i]);

}
int main()
{
    f>>n>>m;
        while(m--)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(j=1;j<=n;j++)
        if(viz[j]==0)
        {
            cnt++;
            dfs(j);
        }
        g<<cnt;
    return 0;
}