#include <fstream>
#include <vector>

using namespace std;

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

const int nmax=100000;
vector <int> g[nmax+1];
bool d[nmax+1];

void dfs(int x)
{
    d[x]=1;
    for(int i=0;i<(int)g[x].size();i++)
    {
        int y=g[x][i];
        if(d[y]==0)
        {
            dfs(y);
        }
    }
}

int main()
{
    int n,m;
    fin>>n>>m;
    for(int i=0;i<m;++i)
    {
        int x,y;
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int sol=0;
    for(int i=1;i<=n;i++)
    {
        if(d[i]==0)
        {
            dfs(i);
            sol++;
        }
    }
    fout<<sol<<"\n";
    return 0;
}