#pragma GCC optimize ("03,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int const MAX=1e5+5;
vector<int>vecini[MAX];
bool viz[MAX];
void myfill(int x)
{
    viz[x]=1;
    int i;
    for(i=0;i<vecini[x].size();++i)
        if(viz[vecini[x][i]]==0)
            myfill(vecini[x][i]);
}
int main()
{
    int n,m;
    f>>n>>m;
    int i;
    int x,y;
    for(i=1;i<=m;++i)
    {
        f>>x>>y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }
    int cnt=0;
    for(i=1;i<=n;++i)
        if(viz[i]==0)
        {
            ++cnt;
            myfill(i);
        }
    g<<cnt;
    return 0;
}