#include<cstdio>
#include<vector>
using namespace std;
bool viz[100100];
vector <int> vec[100100];
void dfs(int nod)
{
    int i;
    viz[nod]=1;
    for(i=0;i<vec[nod].size();i++)
    {
        if(!viz[vec[nod][i]])
        {
            dfs(vec[nod][i]);
        }

    }
}
int main()
{
    int n,m,i,x,y,rez=0;
    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);
        vec[y].push_back(x);
        vec[x].push_back(y);
    }
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            viz[i]=1;
            dfs(i);
            rez++;
        }
    }
    printf("%d",rez);
    return 0;
}