#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int N,M,x,y,viz[100010],count;
vector <int> v[100010];
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();++i)
        if(!viz[v[nod][i]])
            dfs(v[nod][i]);
}
int main()
{
    in>>N>>M;
    for(int i=1;i<=M;++i)
    {
        in>>x>>y;
        v[y].push_back(x);
        v[x].push_back(y);
    }
    for(int i=1;i<=N;++i)
        if(!viz[i])
        {
            ++count;
            dfs(i);
        }
    out<<count;
    return 0;
}