#include <bits/stdc++.h>
using namespace std;
const int N = 15;
int n, ans, color[N];
struct Node{
    int x, y;
} a[N];

void dfs(int u){
    if(u>5){
        bool flag = true;
        for (int i = 1;i<=n;i++){
            if(color[a[i].x]==color[a[i].y]){
                flag = false;
                break;
            }
    }
    if (flag) ans++;
    return;
    }
    for (int i = 1; i <= 4;i++){
        color[u]=i;
        dfs(u + 1);
    }
}
int main() {
    cin>>n;
    for (int i = 1; i <= n; i++) cin >> a[i].x >> a[i].y;
    dfs(1);
    cout<<ans<<endl;
    return 0;
}