#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

const int N=1024;
vector<int>a1[N];
bool viz[N];

int n,m;
void read()
{
    int x,y;
    in>>n>>m;
    for(;m>=1;m--)
    {
        in>>x>>y;
        a1[x].push_back(y);
        a1[y].push_back(x);
    }
}
int grade(int node)
{
    return a1[node].size();
}
void dfs(int node)
{
    viz[node]=1;
        //cout<<node<<" ";
    for(unsigned int i=0;i<a1[node].size();i++)
        {
            if(!viz[a1[node][i]])
                dfs(a1[node][i]);
        }
}
int main()
{
    read();
    int c=0;
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i);
            c++;
        }
    out<<c<<"\n";
    return 0;
}