#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m;
vector <int> V[100005];
bool viz[100005];

void dfs(int x)
{
    viz[x]=1;
    vector <int>::iterator it;
    for(it=V[x].begin();it!=V[x].end();++it)
        if(!viz[*it])
         dfs(*it);

}

int main()
{  fin>>n>>m;
 int i,x,y,ct=0;
   for(i=1;i<=m;++i)
   { fin>>x>>y;
       V[x].push_back(y);
       V[y].push_back(x);
   }

    for(i=1;i<=n;++i)
        if(viz[i]==0)
    {
        ++ct;
        dfs(i);
    }
    fout<<ct;
    return 0;
}