#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector < int > v[100005];
int n,m,cnt;
bool viz[100005];
void read()
{
     in >> n >> m;
     int x,y;
     for(int i=1; i<=m; i++)
     {
     in >> x >> y;
     v[x].push_back(y);
     v[y].push_back(x);
     }
}
void dfs( int nod )
{
     viz[nod] = 1;
     for(int i=0; i<v[nod].size(); i++)
          if( !viz[ v[nod][i] ] ) dfs(v[nod][i]);
}
int main()
{
     read();
     for(int i=1; i<=n; i++)
          if( !viz[i] ) cnt++, dfs(i);
          out << cnt;
    return 0;
}