#include<cstdio>
#include<vector>
using namespace std;
int n,m;
bool viz[100001];
vector <int> l[100001];




void dfs(int u)
{
    vector<int>::iterator it;
    viz[u]=1;
    for(it=l[u].begin();it!=l[u].end();++it)
        if(viz[*it]==0)
            dfs(*it);
}



int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int i,u,v,num;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;++i)
    {
        scanf("%d%d",&u,&v);
        l[u].push_back(v);
        l[v].push_back(u);
    }
    num=0;
    for(i=1;i<=n;++i)
        if(viz[i]==0)
        {
            ++num;
            dfs(i);
        }
    printf("%d\n",num);
    return 0;
}