#include <cstdio>
# include <vector>
using namespace std;
 
vector <int> v[100010];
int i,n,m,s,nr,x,y;
bool use[100010];
 
void dfs(int s)
{
    int i;
    use[s]=true;
    for (i=0; i<v[s].size(); i++)
        if (use[v[s][i]]==false)
        {
            dfs(v[s][i]);
        }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d",&n,&m);
    for (i=1; i<=m; i++)
    {
        scanf("%d %d\n",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i=1;  i<=n; i++)
         if (use[i]==false)
        {
            nr++;
            dfs(i);
        }
    printf("%d\n",nr);
    return 0;
}