#include <iostream>
#include <fstream>
#include <vector>
#define nmax 100005
using namespace std;
int i,n,j,a,b,x,y,m,comp;
bool seen[nmax];
vector <int> v[nmax];
ifstream f("dfs.in");
ofstream g("dfs.out");


void dfs(int x)
{
    seen[x]=1;

   for (int i =0;i<v[x].size();i++)
    {
        y=v[x][i];

        if(!seen[y]) dfs(y);
    }
}



int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

   for(j=1;j<=n;j++)
   {
        if(!seen[j]){comp++;dfs(j);}
   }


g<<comp;


    return 0;
}