#include <cstdio>
#include <algorithm>
#define Maxn 100001
#include <vector>

using namespace std;
int n, m, S, x, y, i;
vector <int> v[Maxn];
int viz[Maxn];
void dfs(int nod)
{
    viz[nod] = 1;
    for (int j = 0; j < v[nod].size(); ++ j)
        if (!viz[v[nod][j]])
        {
            dfs(v[nod][j]);
            viz[v[nod][j]] = 1;
        }
}
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);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i = 1; i <= n; ++ i)
        if(!viz[i])
        {
            dfs(i);
            S ++;
        }
    printf("%d", S);

    return 0;
}