#include <bits/stdc++.h>
#define Nmax 100003
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
bitset <Nmax>used;
vector <int>Neighbour[Nmax];
int N,M,x,y,node,i,Nr;

void dfs(int v)
{
    used[v]=1;
    for(unsigned k=0;k<Neighbour[v].size();k++)
    {
        node=Neighbour[v][k];
        if(used[node]==0)dfs(node);
    }
}
int main()
{
    f>>N>>M;
    while(f>>x>>y)
    {
        Neighbour[x].push_back(y);
        Neighbour[y].push_back(x);
    }
    for(i=1;i<=N;i++)
    if(used[i]==0)Nr++,dfs(i);
    g<<Nr;
    return 0;
}