#include <iostream>
#include <fstream>
#include <vector>
#define NMax 100001
using namespace std;
vector<int> V[NMax];
int v[NMax],N,M,x,y;
ifstream g("dfs.in");
ofstream f("dfs.out");

void Citire()
{
    g>>N>>M;
    for(int i=0;i<M;i++)
    {
        g>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
}

void DFS(int x)
{
    v[x]=1;
    for(int i=0;i<V[x].size();i++)
        if(v[V[x][i]]==0)
        DFS(V[x][i]);
}

void solve()
{
    int rez=0;
    for(int i=1;i<=N;i++)
    {
        if(v[i]==0)
        {
            DFS(i);
            ++rez;
        }
    }
    f<<rez;
}

int main()
{
    Citire();
    solve();
}