### BUGGY CODE ###

import sys

h, *ppp = map(int, sys.stdin.buffer.read().split())
n = 1 << (h - 1)
ppp = [p + n - 1 for p in ppp]
MOD = 10 ** 9 + 7

cumprods = [1] * (2 * n)  # 根から頂点vまでの経路の累積積
cumprods_rev = [1] * n  # ..の逆数
cumprods_through = [0] * n  # 木1の根から木2の根まで、木1の i 番目の葉を経由する経路の積
for i in range(2, 2 * n):
    cumprods[i] = cumprods[i >> 1] * i % MOD
for i in range(n):
    cumprods_rev[i] = pow(cumprods[i], MOD - 2, MOD)
    cumprods_through[i] = cumprods[i + n] * cumprods[ppp[i]] % MOD

# 現在考慮中の木1側のLCAを起点として、木2側の各頂点に至るまでの累積積
# 木1からたどり着かないものは0
cumprods_from_tree1 = [0] * (2 * n)

ans = 0

for lca in range(1, n):
    digit = h - lca.bit_length()
    leftmost_leaf_in_left_subtree = lca << digit
    leftmost_leaf_in_right_subtree = ((lca << 1) + 1) << (digit - 1)
    rightmost_leaf_in_right_subtree = (lca + 1) << digit

    rev = cumprods_rev[lca >> 1]
    for leaf in range(leftmost_leaf_in_left_subtree, leftmost_leaf_in_right_subtree):
        v = ppp[leaf - n]
        cp = cumprods_through[leaf - n] * rev % MOD
        while v > 1:
            cumprods_from_tree1[v] += cp * cumprods_rev[v >> 1] % MOD
            v >>= 1

    rev = cumprods_rev[lca]
    for leaf in range(leftmost_leaf_in_right_subtree, rightmost_leaf_in_right_subtree):
        v = ppp[leaf - n]
        cp = cumprods_through[leaf - n] * rev % MOD
        while v > 1:
            ans = (ans + cumprods_from_tree1[v ^ 1] * cp * cumprods_rev[v >> 2]) % MOD
            v >>= 1

    for leaf in range(leftmost_leaf_in_left_subtree, leftmost_leaf_in_right_subtree):
        v = ppp[leaf - n]
        while cumprods_from_tree1[v] != 0:
            cumprods_from_tree1[v] = 0
            v >>= 1

print(ans)


### FIXED CODE ###

import sys

h, *ppp = map(int, sys.stdin.buffer.read().split())
n = 1 << (h - 1)
ppp = [p + n - 1 for p in ppp]
MOD = 10 ** 9 + 7

cumprods = [1] * (2 * n)  # 根から頂点vまでの経路の累積積
cumprods_rev = [1] * n  # ..の逆数
cumprods_through = [0] * n  # 木1の根から木2の根まで、木1の i 番目の葉を経由する経路の積
for i in range(2, 2 * n):
    cumprods[i] = cumprods[i >> 1] * i % MOD
for i in range(n):
    cumprods_rev[i] = pow(cumprods[i], MOD - 2, MOD)
    cumprods_through[i] = cumprods[i + n] * cumprods[ppp[i]] % MOD

# 現在考慮中の木1側のLCAを起点として、木2側の各頂点に至るまでの累積積
# 木1からたどり着かないものは0
cumprods_from_tree1 = [0] * (2 * n)

ans = 0

for lca in range(1, n):
    digit = h - lca.bit_length()
    leftmost_leaf_in_left_subtree = lca << digit
    leftmost_leaf_in_right_subtree = ((lca << 1) + 1) << (digit - 1)
    rightmost_leaf_in_right_subtree = (lca + 1) << digit

    rev = cumprods_rev[lca >> 1]
    for leaf in range(leftmost_leaf_in_left_subtree, leftmost_leaf_in_right_subtree):
        v = ppp[leaf - n]
        cp = cumprods_through[leaf - n] * rev % MOD
        while v > 1:
            cumprods_from_tree1[v] += cp * cumprods_rev[v >> 1] % MOD
            v >>= 1

    rev = cumprods_rev[lca]
    for leaf in range(leftmost_leaf_in_right_subtree, rightmost_leaf_in_right_subtree):
        v = ppp[leaf - n]
        cp = cumprods_through[leaf - n] * rev % MOD
        while v > 1:
            ans = (ans + cumprods_from_tree1[v ^ 1] * cp * cumprods_rev[v >> 2]) % MOD
            v >>= 1

    for leaf in range(leftmost_leaf_in_left_subtree, leftmost_leaf_in_right_subtree):
        v = ppp[leaf - n]
        while cumprods_from_tree1[v] != 0:
            cumprods_from_tree1[v] = 0
            v >>= 1

print(ans)