#include <fstream>
using namespace std;
ifstream fin("subgraf1.in");
ofstream fout("subgraf1.out");
int n,x,y,i,j,nr,viz[101],a[101][101];
int main()
{
    fin>>n;
    while(fin>>x>>y)
        a[x][y]=a[y][x]=1;
    for(i=1;i<=n;i++)
        {
            for(j=1;j<=n;j++)
            if(a[i][j]==1)
                a[i][n+1]++;
            if(a[i][n+1]<mmin)
                mmin=a[i][n+1];
        }
    for(i=1;i<=n;i++)
        if(a[i][n+1]==mmin)
            for(j=1;j<=n;j++)
                a[i][j]=a[j][i]=0;
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            if(a[i][j]==1) nr++;
    fout<<nr/2<<'\n';
    return 0;
}