#include <cstdio>
#include <vector>
using namespace std;
vector<int> G[100001];
int i, N, M, x, y, nr, Sel[100001];
inline void dfs(int x)
{
    vector<int> ::iterator it;
    Sel[x]=1;
    for (it=G[x].begin(); it!=G[x].end(); it++)
        if (!Sel[*it]) dfs(*it);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d", &N, &M);
    for (i=1; i<=M; i++)
    {
        scanf("%d%d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (i=1; i<=N; i++)
        if (!Sel[i])
        {
            dfs(i);
            nr++;
        }
    printf("%d\n", nr);
    return 0;
}