#include <fstream>
#include <vector>

using namespace std;

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

const int N=1e5 + 1;

vector<int> a[N];

bool viz[N];

int n,m,contor;

void dfs(int nod)
{
    viz[nod]=1;
    for(auto y:a[nod])
    {
        if(!viz[y])
        {
            dfs(y);
        }
    }
}

int main()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            contor++;
            dfs(i);
        }
    }
    out<<contor;
    return 0;
}