#include <cstdio>
#include <vector>

using namespace std;

vector<int> g[100001];
bool vis[100001];

void dfs(int node)
{
    vis[node] = 1;
    for (int i = 0; i < g[node].size(); ++i)
        if (!vis[g[node][i]])
            dfs(g[node][i]);
}

int main()
{
    FILE *in = fopen("dfs.in", "r");
    FILE *out = fopen("dfs.out", "w");

    int n, m;
    fscanf(in, "%d%d", &n, &m);

    for (int x, y; m > 0; --m)
    {
        fscanf(in, "%d%d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }

    int sol = 0;
    for (int i = 1; i <= n; ++i)
        if (!vis[i])
        {
            sol++;
            dfs(i);
        }
    fprintf(out, "%d\n", sol);

    return 0;
}