#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100001];
bool viz[100001];
int n,m,x,y,comp;
void dfs(int k)
{
    viz[k]=1;
    for(vector <int>::iterator it = v[k].begin(); it != v[k].end(); ++ it)
        if(!viz[*it])
            dfs(*it);
}
int main()
{
    fin>>n>>m;
    while(m--)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; ++i)
        if(!viz[i])
        {
            comp++;
            dfs(i);
        }
    fout<<comp;
    return 0;
}