CF1594E1 Rubik‘s Cube Coloring (easy version)

又是没弄懂的一题

#include<bits/stdc++.h> 
#define int long long
using namespace std;const int mod = 1e9 + 7;
signed main()
{
    int n; cin >> n;int f[100005];f[1] = 16;for (int i = 2; i <= n + 1; i ++ ){
    f[i] =  (f[i - 1] * f[i - 1]) % mod * 16 % mod;}f[0] = 1;cout << f[n - 1] * 6 % mod<< endl;return 0;
}