#include<bits/stdc++.h>
using namespace std;
#define pb push_back
vector <int> my[100005];vector <bool> viz(100005,false);
inline void dfs(int nod){for (auto x: my[nod])if (!viz[x]) viz[x]= true,dfs(x);}
int main(){ifstream fin("dfs.in");ofstream fout("dfs.out");s	
	int n,m, count=0;fin>>n>>m;
	for(int i(1),x,y;i<=m;i++){fin>>x>>y;my[x].pb(y);my[y].pb(x);}
for(int i(1);i<=n;i++){if(!viz[i]){viz[i]=true;count++;dfs(i);}}
	fout<<count;
	return 0;
}