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

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector <int> V[DMAX];
bool uz[DMAX];

int n,m,comp;

void citire();
void dfs(int node);

int main()
{int i;
 citire();
 for(i=1;i<=n;i++)
     if(!uz[i])
        {dfs(i);
         comp++;
        }
 fout<<comp<<'\n';
 return 0;
}
void citire()
{int i,x,y,c;
 fin>>n>>m;
 for(i=0;i<m;i++)
     {fin>>x>>y;
      V[x].push_back(y);
      V[y].push_back(x);
     }
}
void dfs(int node)
{int i;
 uz[node]=true;
 for(i=0;i<V[node].size();i++)
     if(!uz[V[node][i]])
        dfs(V[node][i]);
}