#include <cstdio>
#include <vector>
#include <deque>
#define N 100010
using namespace std;
vector<int> v[N];
deque<int> Q;
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++;
            Q.resize(0);Q.push_back(i);viz[i]=1;
            for(;Q.size();)
            {
                j=Q.front();Q.pop_front();
                for(vector<int>::iterator it=v[j].begin();it!=v[j].end();it++)
                    if(!viz[*it])
                    {
                        viz[*it]=1;
                        Q.push_back(*it);
                    }
            }
        }
    printf("%d\n",nc);
    return 0;
}