#include <bits/stdc++.h>
#define Nmax 100005
using namespace std;


ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m,sol;
bool viz[Nmax];
vector <int > G[Nmax];

void dfs(int nod)
{
    viz[nod] = 1;
    for(unsigned int i = 0; i < G[nod].size(); i++)
    {
        int vecin = G[nod][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}

int main()
{
   f>>n>>m;
   for(int i = 1; i <= m; i++)
   {
       int x,y;
       f>>x>>y;
       G[x].push_back(y);
       G[y].push_back(x);
   }

   for(int i = 1; i <= n; i++)
    if(!viz[i])
   {
       sol++;
       dfs(i);
   }
    g<<sol;
    return 0;
}