#include using namespace std; struct iofast_t { iofast_t() { ios::sync_with_stdio(false); cin.tie(nullptr); } } iofast; struct uns_t {} uns; template auto vec(Element init, Head arg, Args ...args) { if constexpr (sizeof...(Args) == 0) return vector(arg, init); else return vector(arg, vec(init, args...)); } template auto vec(uns_t, Head arg, Args ...args) { return vec(Element(), arg, args...); } template auto distance(const Container &c, decltype(begin(c)) iter) { return distance(begin(c), iter); } template ::value_type>> auto isort(RIter first, RIter last, Compare comp = Compare()) { vector i(distance(first, last)); iota(begin(i), end(i), 0); sort(begin(i), end(i), [&](auto x, auto y) { return comp(*(first + x), *(first + y)); }); return i; } template typename, typename = void_t<>> struct detect : false_type {}; template typename Check> struct detect>> : true_type {}; template typename Check> constexpr inline bool detect_v = detect::value; template using has_member_sort = decltype(declval().sort()); template > auto sorted(Container c, Compare comp = Compare()) { if constexpr (detect_v) { c.sort(comp); return c; } else { sort(begin(c), end(c), comp); return c; } } template > auto uniqued(Container c, Compare comp = Compare()) { c.erase(unique(begin(c), end(c), comp), end(c)); return c; } template > T &chmin(T &l, T r, Compare &&f = less()) { return l = min(l, r, f); } template > T &chmax(T &l, T r, Compare &&f = less()) { return l = max(l, r, f); } #include using mint = atcoder::modint1000000007; int main() { int n; cin >> n; if (n < 4) { cout << 0 << endl; return 0; } auto dp = vec(0, n + 1, 1 << 4); fill(begin(dp[4]), end(dp[4]), 1); dp[4][0b1010] = 0; for (int i = 5; i <= n; ++i) { for (int j = 0; j < (1 << 4); ++j) { if (j == 0b1010) { continue; } dp[i][j] += dp[i - 1][(((j << 1) | 0) & ((1 << 4) - 1))]; dp[i][j] += dp[i - 1][(((j << 1) | 1) & ((1 << 4) - 1))]; } } cout << (mint(2).pow(n) - accumulate(begin(dp[n]), end(dp[n]), mint(0))).val() << endl; }