#include <fstream>
#include <vector>

using namespace std;

ifstream cin ("dfs.in");
ofstream cout ("dfs.out");

int n,m,i,x,y,ok[100005],vec,nr;
vector<int>v[100005];

void dfs(int node)
{
    ok[node]=1;
    for(int i=0;i<v[node].size();i++)
    {
        int vec=v[node][i];
        if(ok[vec] == 0)
            dfs(vec);
    }
}
int main()
{
    cin>>n>>m;
    for(i=1;i<=m;i++)
    {
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(ok[i]==0)
        {
            dfs(i);
            nr++;
        }
    cout<<nr;
    return 0;
}