#include <fstream>
#include <vector>

using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");

#define MAXN 100005
#define INF 0x3f3f3f3f

vector<int > graf[MAXN];
bool fol[MAXN];
int n,m,nrc,i,j,x,y;

void dfs(int nod)
{
    for(int i=0; i < graf[nod].size(); i++)
        if(!fol[graf[nod][i]])
        {
            fol[graf[nod][i]] = true;
            dfs(graf[nod][i]);
        }
}
int main()
{
    cin>>n>>m;
    for(i=1; i<=m; i++)
    {
        cin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    for(i=1; i<=n; i++)
    {
        if(!fol[i])
            dfs(i), nrc++;
    }

    cout << nrc;
    return 0;
}