#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int nmax = 100005;
vector<int>g[nmax];
int f[nmax];

void dfs(int node)
{
    f[node] = 1;
    for(int i = 0; i < g[node].size(); i++)
    {
        int vecin = g[node][i];
        if(f[vecin] == 0)
            dfs(vecin);
    }
}
int main()
{
    int n,m;
    in>>n>>m;
    for(int i = 1; i <= m; i++)
    {
        int x,y;
        in>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int comp = 0;
    for(int i = 1; i <= n; i++)
        if(f[i] == 0)
        {
            dfs(i);
            comp++;
        }
    out<<comp;
    return 0;
}