#include <cstdio>
#include <vector>
#define pb push_back

using namespace std;

vector <int> G[100010];
int n, i, nr, m, x, y;
bool sel[100010];

void dfs(int x){

  vector <int> :: iterator it;

  sel[x] = true;
  for(it=G[x].begin(); it != G[x].end(); it++)
    if(!sel[*it]) dfs(*it);

}


int main()
{
    freopen("dfs.in","r", stdin);
    freopen("dfs.out","w", stdout);
    scanf("%d %d\n", &n, &m);
    for(int i=1; i<=m; i++)
    {
        scanf("%d %d\n", &x, &y);
        G[x].pb(y);
        G[y].pb(x);
    }
    nr=0;
    for(int i=1; i<=n; i++)
    if(!sel[i]){
        nr++;
        dfs(i);
    }
    printf("%d\n", nr);
    return 0;
}