#include <fstream>
#include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

void DFS(int node, vector<vector<int> > &L, vector<bool> &visited)
{
    visited[node] = true;
    for(auto neighbour : L[node])
        if(!visited[neighbour])
            DFS(neighbour,L,visited);
}

int main()
{
    int N, M, result=0;
    f>>N>>M;
    vector<vector<int> > L(N+1);
    for(int i = 0; i < M; i++)
    {
        int A, B;
        f>>A>>B;
        L[A].push_back(B); L[B].push_back(A);
    }
    vector<bool> visited(N+1,false);
    for(int i = 1; i <= N; i++)
    {
        if(!visited[i])
        {
            result++;
            DFS(i,L,visited);
        }
    }
    g<<result;
    return 0;
}