# include <cstdio>
# define pb push_back
# include <vector>
using namespace std;
int n,m,i,k,viz[100001],x,y;
vector <int>G[100001];
void DFS(int x)
{
    int i;
    viz[x]=1;
    for(i=0;i<G[x].size();++i)
        if(!viz[G[x][i]])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].pb(y);G[y].pb(x);
    }
    for(i=1;i<=n;++i)
        if(!viz[i])
        {
            k++;
            DFS(i);
        }
    printf("%d\n",k);
    return 0;
}