#include <fstream>
#include <vector>

using namespace std;
ifstream fi("dfs.in");
ofstream fo("dfs.out");
const int nmax=1e5;
int n, m, cnt;
int viz[nmax+5];
vector <int> G[nmax+5];

void dfs(int nod)
{
    viz[nod]=1;
    for(auto vec:G[nod])
        if(!viz[vec])
            dfs(vec);
}

int main()
{
    fi>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x, y;
        fi>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            cnt++;
            dfs(i);
        }
    fo<<cnt;
    fi.close();
    fo.close();
    return 0;
}