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

using namespace std;
ifstream  fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100002];
int n,m,x,y,contor,viz[100002];

void dfs(int vi)
{
    viz[vi]=1;
    for(int i=0;i<v[vi].size();i++)
    {
        if(viz[v[vi][i]]==0)
            {
                dfs(v[vi][i]);
            }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
            {dfs(i);
            contor++;
            }
    }
    fout<<contor;
    return 0;
}