#define NMAX 100005
#include <cstdio>
#include <vector>
using namespace std;

vector<int> graph[NMAX];
int viz[NMAX], n, m;

void read()
{
    int x, y;

    freopen("dfs.in", "r", stdin);
    scanf("%d %d", &n, &m);
    for(int i=0; i<m; ++i)
    {
        scanf("%d %d", &x, &y);
        graph[x].push_back(y);
        graph[y].push_back(x);
    }

}

void parcCC(int i)
{
    viz[i] = 1;
    for(auto &v:graph[i])
        if(viz[v] == 0)
            parcCC(v);
}


void findCC()
{
    freopen("dfs.out", "w", stdout);
    int nCC = 0;
    for(int i=1; i<=n; ++i)
        if(viz[i] == 0)
        {
            ++nCC;
            parcCC(i);
        }
    printf("%d", nCC);
}


int main()
{
    read();
    findCC();
    return 0;
}