#include <fstream>
#include <vector>
#include <bitset>
#include <string.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int const nm=100001;
vector<int>v[nm];
bitset<nm>check;int cnt=0;
void dfs(int cord){
    check[cord]=1;
    for(int i=0;i<v[cord].size();++i)
    {
        int r=v[cord][i];
        if(!check[r])
            dfs(r);
    }
    }
int main()
{
    int n,m,i,a,b;
    f>>n>>m;
    for(i=1;i<=m;++i)
    {
        f>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(i=1;i<=n;++i)
        if(!check[i])
            ++cnt,dfs(i);
    g<<cnt;
    return 0;
}