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