#include <cstdio>
# include <cstring>
# include <vector>
using namespace std;
vector <int> v[100010];
int i,j,x,y,n,m,nr;
bool ok[100010];
void dfs(int i)
{
    ok[i]=true;
    for (int j=0; j<v[i].size(); j++)
       if (ok[v[i][j]]==false) dfs(v[i][j]);
}

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