#include <cstdio>
#include <vector>
#define Nmax 100005

using namespace std;

bool viz[Nmax];
vector <int> L[Nmax];

inline void Dfs(int nod)
{
    int i,len=L[nod].size();
    viz[nod]=true;
    for(i=0;i<len;++i)
        if(!viz[L[nod][i]])
            Dfs(L[nod][i]);
}

int main()
{
    int N,M,x,y,i,sol=0;
    freopen ("dfs.in","r",stdin);
    freopen ("dfs.out","w",stdout);
    scanf("%d%d", &N,&M);
    while(M--)
    {
        scanf("%d%d", &x,&y);
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1;i<=N;++i)
        if(!viz[i])
        {
            ++sol;
            Dfs(i);
        }
    printf("%d\n", sol);
    return 0;
}