#include<fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int i,n,x,y,m,sol,finish;
bool viz[100012];
vector <int> v[100012];
void dfs(int nod)
{
    viz[nod]=1;
    for(int it=0,finish=v[nod].size();it<finish;++it)
        if(!viz[v[nod][it]]) dfs(v[nod][it]);
}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;++i)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;++i)
        if(!viz[i]) ++sol,dfs(i);
    g<<sol;
    return 0;
}