#include<cstdio>
#include<vector>

using namespace std;

vector<int> a[100004];
int n,m,i,nr,x,y;
bool sel[100004];

void dfs(int nod)
{
    sel[nod]=true;
    for(int i=0;i<a[nod].size();i++)
    {
        if(!sel[a[nod][i]])
        {
            dfs(a[nod][i]);
        }
    }
}

int main()
{
    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(!sel[i])
        {
            dfs(i);
            nr++;
        }
    }
    printf("%d\n",nr);
    return 0;
}