#include <fstream>
#include <vector>

using namespace std;

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

int viz[100005],N,M,x,y,nrcomp;
vector <int> v[100005];

void DFS(int x)
{
    int i,y;
    viz[x]=1;
    int nrvecini=v[x].size();
    for(i=0;i<nrvecini;i++)
    {
        y=v[x][i];
        if(!viz[y])
            DFS(y);
    }
}

int main()
{int i;
    f>>N>>M;
    for(i=1;i<=M;i++)
    {
        f>>N>>M;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=N;i++)
    {
        if(!viz[i])
        {
            nrcomp++;
            DFS(i);
        }
    }
    g<<nrcomp;
    return 0;
}