#include <iostream>
#include<bits/stdc++.h>

using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

int n, m;
const int NMAX=100001;
vector < int > Edge[NMAX];
bitset < NMAX > Used;

void Read()
{
    int x, y;
    in>>n>>m;
    for(int i=1; i<=m; i++)
        in>>x>>y, Edge[x].push_back(y), Edge[y].push_back(x);
}

void DFS(int Node)
{
    int lim=Edge[Node].size();
    Used[Node]=1;
    for(int i=0; i<lim; i++)
    {
        int next=Edge[Node][i];
        if(!Used[next])
            DFS(next);
    }

}

int main()
{
    Read();
    int Comp_Conex=0;
    for(int i=1; i<=n; i++)
        if(!Used[i])
            Comp_Conex++, DFS(i);
    out<<Comp_Conex;
    return 0;
}