#include <fstream>
#include <bitset>
#include <vector>
#define MAXN 100001
using namespace std;
ifstream fi("dfs.in");
ofstream fo("dfs.out");

bitset <MAXN> V;
vector <int> vecin[MAXN];
int element,n,m,x,y;

void parcurgere(int x)
{
    V[x]=1;
    for (int i=0; i<vecin[x].size(); i++)
    {
        if (V[vecin[x][i]]==0)
            parcurgere(vecin[x][i]);
    }
}

int main()
{
    fi>>n>>m;
    for (int i=1; i<=m; i++)
    {
        fi>>x>>y;
        vecin[x].push_back(y);
        vecin[y].push_back(x);
    }
    for (int i=1; i<=n; i++)
        if (V[i]==0)
        {
            element++;
            parcurgere(i);
        }
    fo<<element;
    fi.close();
    fo.close();
    return 0;
}