#include <fstream>
using namespace std;

int n, a[1000][1000], m, viz[1000];
ifstream f("dfs.in");
ofstream g("dfs.out");

void citire()
{
    f>>n>>m;
    for(int i=0;i<m;i++)
    {
            int x, y;
            f>>x>>y;
            a[x][y] = a[y][x] = 1;
    }

}


void dfs(int x)
{
    viz[x] = 1;
    for(int i=1;i<=n;i++)
        if(a[x][i] == 1 && viz[i] == 0)
            dfs(i);
}


int numar()
{
    int nc = 0;
    for(int i=1;i<=n;i++)
        if(viz[i] == 0)
        {
            nc++;
            dfs(i);
        }
        return nc;
}

int main()
{
    citire();
    g<<numar();
    return 0;
}