#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fi("dfs.in");
ofstream fo("dfs.out");
int n,m;
vector <int>V[100001];
int freQ[100001];
void DFS(int x)
{
    freQ[x]=1;
    for(int i=0;i<V[x].size();i++)
    {
        int vecin=V[x][i];
        if(freQ[vecin]==0)
            DFS(vecin);
    }
}
int main()
{
    fi>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fi>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    int cmpConex=0;
    for(int i=1;i<=n;i++)
    {
        if(freQ[i]==0)
        {
            cmpConex++;
            DFS(i);
        }
    }
    fo<<cmpConex;
    return 0;
}