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

using namespace std;

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

const int M=100005;
int n,m,x,y,viz[M],cnt;
vector < int > v[M];

void DFS(int nod)
{
    viz[nod]=1;
    for(auto vec : v[nod])
        if(!viz[vec])
            DFS(vec);
}

int main()
{
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            DFS(i);
            cnt++;
        }
    fout << cnt;
    return 0;
}