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

using namespace std;

vector <int> graf[100005];
int viz[100005];
void DFS(int nod, int N)
{
    viz[nod]=1;
    int lim=graf[nod].size();
    for(int i=0;i<lim;i++)
        if(viz[graf[nod][i]]==0)
        DFS(graf[nod][i],N);
}
int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int N,M,i,x,y,c=0;
    in>>N>>M;
    for(i=1;i<=M;i++)
    {
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(i=1;i<=N;i++)
        if(viz[i]==0)
        {
            c++;
            DFS(i,N);
        }
    out<<c;
    return 0;
}