#include <fstream>
#include <vector>
#include <queue>
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

const int inmax=100000;
vector<int> q[inmax+1];
bool d[inmax+1];
void DFS(int x)
{
d[x]=1;
for(int i=0;i<(int)q[x].size();i++)
{
int y=q[x][i];
if(d[y]==0)
DFS(y);
}
}

int main()
{
int n,m;
f>>n>>m;
for(int i=0;i<m;++i)
{
    int x,y;
    f>>x>>y;
    q[x].push_back(y);
q[y].push_back(x);
}
int sol=0;
for(int i=1;i<=n;i++)
{
if(d[i]==0)
{
    DFS(i);
    sol++;
}
}
g<<sol<<"\n";
    return 0;
}