#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;
vector<int> Graf[100005];
int viz[100005],N,M;

void read()
{
    scanf("%d%d",&N,&M);
    int a,b;
    for(int i = 1; i <= M; ++i)
    {
        scanf("%d%d",&a,&b);
        Graf[a].push_back(b);
        Graf[b].push_back(a);
    }
}
void DFS(int k)
{
    viz[ k ] = 1;
    for(vector<int>::iterator it = Graf[k].begin(); it != Graf[k].end(); ++it)
        if(!viz[*it])
            DFS(*it);
}

void solve()
{
    int ncc = 0;
    for(int i = 1; i <= N; ++i)
        if(!viz[i])
        {
            ++ncc;
            DFS(i);
        }
    printf("%d\n",ncc);
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    read();
    solve();

    return 0;
}