#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <bitset>
#include <stack>
#define nmax 100005
using namespace std;

int n,m1;
vector<int> m[nmax];
bitset <nmax> viz;
stack<int> s;
int nr;

inline void dfs(int nod)
{
   int crt;
   vector<int>::iterator it;
   s.push(nod);
   while(!s.empty())
   {
       crt=s.top(); s.pop(); viz[crt]=1;
       for(it=m[nod].begin();it!=m[nod].end();it++)
            if(!viz[*it])
                s.push(*it);
   }
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m1);
    int n1,n2,i;
    for(;m1;m1--)
    {
        scanf("%d%d",&n1,&n2);
        m[n1].push_back(n2);
        m[n2].push_back(n1);
    }
    for(i=1;i<=n;i++)
    if(!viz[i]) {nr++; dfs(i); }
    printf("%d\n",nr);
    fclose(stdin);
    fclose(stdout);
    return 0;
}