#include<fstream>
using namespace std;
ifstream f("triplete.in");
ofstream g("triplete.out");
int n,m,i,j,k;
short leg[10000][10000];
struct friendship
{
	int x,y;
};
friendship a[66666];
int main()
{
	f>>n>>m;
	for(i=1;i<=m;i++)
	{
		f>>a[i].x>>a[i].y;
		leg[a[i].x][a[i].y]=leg[a[i].y][a[i].x]=1;
	}
	i=1;
	int nr=0;
	while(i<n+1)
	{
		for(j=1;j<=n;j++)
			if(leg[i][j])
				nr++;
		if(nr==3)
			k++;
		nr=0;
		i++;
	}
	g<<k;
	return 0;
}