#include <fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

unsigned a[1000][1000],n,m,i,viz[1000];

void citeste()
    {
        unsigned x,y;
        for(i=1;i<=m;i++)
            {
                fin>>x>>y;
                a[x][y]=1;
                a[y][x]=1;
            }
    }

void dfs(unsigned x)
    {
        unsigned j;

        viz[x]=1;
        for(j=1;j<=n;j++)
            if(viz[j]==0&&a[x][j]!=0)
                dfs(j);
    }


int main()
{
    fin>>n>>m;
    citeste();
    unsigned a=0;
    for(i=1;i<=n;i++)
            if(viz[i]==0)
                {
                    dfs(i);
                    a++;
                }
    fout<<a;
    return 0;
}