#include <fstream>
#include <vector>
#define nmax 100005

using namespace std;

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

vector <int> g[nmax];
int viz[nmax], n, m, i, k;

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

}

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