#include<cstdio>
#include<vector>
using namespace std;
#define NMAX 100005
vector <int> a[NMAX];
int n,m,nr,x,y,v[NMAX];
void dfs(int s)
{
    int i;
    v[s]=nr;
    for (i=0;i<a[s].size();++i)
        if (!v[a[s][i]])
            dfs(a[s][i]);
}
int main()
{
    int i;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1;i<=m;++i)
        {
            scanf("%d%d",&x,&y);
            a[x].push_back(y);
            a[y].push_back(x);
        }
    for (i=1;i<=n;++i)
        if (!v[i])
            {
                ++nr;
                dfs(i);
            }
    printf("%d\n",nr);
    return 0;
}