#include <cstdio>
#include <vector>
using namespace std;
int i,n,m,x,nr,y;
bool sel[100004];
vector<int> g[100004];
void dfs (int x)
{
    int i;
    sel [x]=true;
    for (i=0;i<g[x].size();i++)
        if (sel[g[x][i]]==false)
        dfs (g[x][i]);
}
int main()
{
    freopen ("dfs.in","r",stdin);
    freopen ("dfs.out","w",stdout);
    scanf ("%d %d", &n, &m);
    for (i=1;i<=m;i++)
    {
        scanf ("%d %d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    nr=0;
    for (i=1;i<=n;i++)
        if (sel[i]==false)
        {
               dfs(i);
               nr++;
        }
    printf ("%d", nr);
    return 0;
}