#include <cstdio>
#include <vector>
#define N 100010
using namespace std;
vector<int> v[N];
int n,m,i,j,nc,viz[N];
void dfs(int);
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(;m;m--)
    {
        scanf("%d%d",&i,&j);
        v[i].push_back(j);
        v[j].push_back(i);
    }
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            nc++;
            dfs(i);
        }
    printf("%d\n",nc);
    return 0;
}
void dfs(int nod)
{
    viz[nod]=1;
    for(vector<int>::iterator it=v[nod].begin();it!=v[nod].end();it++)
        if(!viz[*it])
            dfs(*it);
}