#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> G[100005];
int n, m, x, y, i, j, nrc;
bool viz[100005];
void dfs(int nod)
{
    viz[nod]=1;
    for(auto it:G[nod])
        if(!viz[it])
            dfs(it);
}
int main()
{   f>>n>>m;
    for(i=1;i<=m;i++)
    {   f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(!viz[i])
        {   nrc++;
            dfs(i);
        }
    g<<nrc;
    return 0;
}