#include <fstream>

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

int a[1005][1005],i,m,n,v[1005],cnt,x,y;

void dfs(int nod)
{
    int i;
    v[nod]=1;
    for (i=1;i<=n;i++)
    {
        if ((v[i]==0)&&(a[nod][i]==1)) dfs(i);
    }
}

int main()
{
    f>>n>>m;
    for (i=1;i<=m;i++)
    {
        f>>x>>y;a[x][y]=1;a[y][x]=1;
    }

    for (i=1;i<=n;i++)
    {
        if (v[i]==0)
        {
            cnt++;
            dfs(i);
        }
    }
    g<<cnt;
}