#include <cstdio>
# include <vector>
using namespace std;

vector <int> v[100010];
bool ok[100010];
int n,i,j,k,m,x,y,nr=0;

void dfs(int k)
{
    int i;
    ok[k]=true;
    for (i=0; i<v[k].size(); i++)
        if (ok[v[k][i]]==false)
            dfs(v[k][i]);
}
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);
    }
    for (i=1; i<=n; i++)
        if (ok[i]==false)
        {
            nr++;
            dfs(i);
        }
    printf("%d\n",nr);
    return 0;
}