#include <fstream>
#include <vector>

using namespace std;

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

typedef vector<int> VI;

vector<VI> G;
vector<bool> viz;
#define foor(it,v) for(__typeof(v.begin()) it=v.begin();it!=v.end();++it)
int n,m,nrc,x,y,i;

void dfs(int nod)
    {
    viz[nod]=true;
    foor(it,G[nod])
    if(!viz[*it]) dfs(*it);
    }

int main()
    {
    f>>n>>m;
    G.resize(n+1);
    viz.resize(n+1);
    for(; m; --m)
        {
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
        }
    for(i=1; i<=n; ++i) if(!viz[i])
            {
            dfs(i),++nrc;
            }
    g<<nrc;
    return 0;
    }