#include<stdio.h>
#include<vector>
# define nmax 100001
using namespace std;
int n,viz[nmax];
vector <int>v[nmax];
inline void dfs(int x)
{
    int i;
    viz[x]=1;
    for(i=0;i<v[x].size();++i)
        if(!viz[v[x][i]])
            dfs(v[x][i]);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
      int i,m,x,y,nr=0;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;++i)
    {
        scanf("%d%d",&x,&y);
        v[x].push_back(y);v[y].push_back(x);
    }
    for(i=1;i<=n;++i)
        if(!viz[i])
        {
            nr++;
            dfs(i);
        }
    printf("%d\n",nr);
    return 0;
}