#include <cstdio>
#include <vector>
using namespace std;
vector <int> g[100005];
bool viz[100005];
int i,n,m,x,y,cnt;
void DFS(int nod)
{
    viz[nod]=1;
    for (int i=0; i<g[nod].size(); i++)
        if (!viz[g[nod][i]])
        DFS(g[nod][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);
    }
    for (i=1; i<=n; i++) if (!viz[i])
    {
        cnt++;
        DFS(i);
    }
    printf("%d\n",cnt);
    return 0;
}