#include <bits/stdc++.h>
#define dim 100010

using namespace std;

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


vector <int> v[dim];
int vaz[dim];
int n , m , x , y , sol = 0, i;

void dfs( int node )
{
    vaz[node] = 1;
    for ( int i = 0 ; i < v[node].size() ; i++ )
        if( vaz[v[node][i]] == 0)
        dfs(v[node][i]);
}
int main()
{
   f >> n >> m;
   for(int  i = 1 ; i <= m ; i++ )
   {
       f >> x >> y ;
       v[x].push_back(y);
       v[y].push_back(x);
   }
   for(int  i = 1 ; i <= n ; i++ )
   if( vaz[i] == 0 )
   {
       sol++;
       dfs(i);
   }
   g << sol;
    return 0;
}