#include <cstdio>
#include <vector>
using namespace std;
int i,j,m,n,x,y,nr;
vector <int> G[900000];
vector <int>::iterator it;
bool ok[999999];
void dfs(int x)
{
    vector <int>::iterator it;
    ok[x]=true;
    for(it=G[x].begin(); it!=G[x].end(); it++)
    {
        if(ok[*it]==false) dfs(*it);
    }
}
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);
        G[x].push_back(y);
        G[y].push_back(x);

    }
    for(i=1; i<=n; i++)
    {
        if(ok[i]==false) {dfs(i);nr++;}
    }
    printf("%d\n",nr);
    return 0;
}