#include <fstream>
#include <vector>
using namespace std;

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

const int N = 100001;

int n, m, c=0;
bool viz[N];
vector<int> ad[N];

void dfs(int x)
{
    viz[x] = true;
    for(int v : ad[x])
        if(!viz[v])
            dfs(v);
}

int main()
{
    fin>>n>>m;
    for(int i=0;i<m;++i)
    {
        int x, y;
        fin>>x>>y;
        ad[x].push_back(y);
        ad[y].push_back(x);
    }

    for(int i=1;i<=n;++i)
        if(!viz[i])
        {
            dfs(i);
            c++;
        }

    fout<<c;
    return 0;
}