#include <fstream>
#include <vector>
#include <deque>
#include <bitset>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[500001];
bitset <100001> viz;
inline void dfs(int x)
{
    viz[x]=1;
    for(vector <int>::iterator it=v[x].begin();it!=v[x].end();it++)
    {
        if(viz[*it]==0)
        {
            dfs(*it);
        }
    }
}
int main()
{
    int n,m,i,x,y;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int sol=0;
    for(i=1;i<=n;i++)
    {
        if(!viz[i]) sol++,dfs(i);
    }
    fout<<sol;
}