#include <cstdio>
#include <algorithm>
#include <vector>
#define maxN 100004
using namespace std;
int n, m, i, nrc, x, y;
vector<int> v[maxN];
bool w[maxN];
void dfs(int nod)
{
    int i;
    w[nod] = true;
    for(i = 0; i < v[nod].size(); i++)
        if(!w[v[nod][i]])
        dfs(v[nod][i]);
}
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(!w[i])
        nrc++, dfs(i);
    printf("%d", nrc);
    return 0;
}