#include <fstream>
#include <vector>
using namespace std;
ifstream fi("dfs.in");
ofstream fo("dfs.out");
int n,m,s,cc[100001];
vector<int>v[100001];
void DFS(int p, int nrcc)
{
    size_t i;
    cc[p] = nrcc;
    for(i=0; i<v[p].size(); i++)
        if(cc[v[p][i]] == 0)
           DFS(v[p][i], nrcc);

}
int main()
{
    int i,x,y, nrcc = 0;
    fi >> n >> m;
    while(fi >> x >> y)
    {
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1; i<=n; i++)
    {
        if(cc[i] == 0)
            DFS(i, ++nrcc);
    }
    fo << nrcc;
    return 0;
}