結果
| 問題 | No.981 一般冪乗根 |
| ユーザー |
 Pachicobue
|
| 提出日時 | 2020-02-07 23:13:54 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
TLE
(最新)
AC
(最初)
|
| 実行時間 | - |
| コード長 | 21,290 bytes |
| コンパイル時間 | 3,219 ms |
| コンパイル使用メモリ | 235,988 KB |
| 実行使用メモリ | 10,624 KB |
| 最終ジャッジ日時 | 2024-10-09 14:35:54 |
| 合計ジャッジ時間 | 18,523 ms |
|
ジャッジサーバーID （参考情報） |
judge1 / judge3 |
（要ログイン）
テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | TLE | - |
| testcase_01 | -- | - |
| testcase_02 | -- | - |
| testcase_03 | -- | - |
| testcase_04 | -- | - |
| testcase_05 | -- | - |
| testcase_06 | -- | - |
| testcase_07 | -- | - |
| testcase_08 | -- | - |
| testcase_09 | -- | - |
| testcase_10 | -- | - |
| testcase_11 | -- | - |
| testcase_12 | -- | - |
| testcase_13 | -- | - |
| testcase_14 | -- | - |
| testcase_15 | -- | - |
| testcase_16 | -- | - |
| testcase_17 | -- | - |
| testcase_18 | -- | - |
| testcase_19 | -- | - |
| testcase_20 | -- | - |
| testcase_21 | -- | - |
| testcase_22 | -- | - |
| testcase_23 | -- | - |
| testcase_24 | -- | - |
| testcase_25 | -- | - |
| testcase_26 | -- | - |
| testcase_27 | -- | - |
| testcase_28 | -- | - |
| evil_60bit1.txt | -- | - |
| evil_60bit2.txt | -- | - |
| evil_60bit3.txt | -- | - |
| evil_hack | -- | - |
| evil_hard_random | -- | - |
| evil_hard_safeprime.txt | -- | - |
| evil_hard_tonelli0 | -- | - |
| evil_hard_tonelli1 | -- | - |
| evil_hard_tonelli2 | -- | - |
| evil_hard_tonelli3 | -- | - |
| evil_sefeprime1.txt | -- | - |
| evil_sefeprime2.txt | -- | - |
| evil_sefeprime3.txt | -- | - |
| evil_tonelli1.txt | -- | - |
| evil_tonelli2.txt | -- | - |
ソースコード
#include <bits/stdc++.h>
// created [2020/02/02] 01:23:57
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
using uint = unsigned int;
using usize = std::size_t;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
template<typename T, usize n>
using arr = T (&)[n];
template<typename T, usize n>
using c_arr = const T (&)[n];
template<typename T>
using max_heap = std::priority_queue<T>;
template<typename T>
using min_heap = std::priority_queue<T, std::vector<T>, std::greater<T>>;
template<typename T> constexpr T popcount(const T u) { return u ? static_cast<T>(__builtin_popcountll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T log2p1(const T u) { return u ? static_cast<T>(64 - __builtin_clzll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T msbp1(const T u) { return log2p1(u); }
template<typename T> constexpr T lsbp1(const T u) { return __builtin_ffsll(u); }
template<typename T> constexpr T clog(const T u) { return u ? log2p1(u - 1) : static_cast<T>(u); }
template<typename T> constexpr bool ispow2(const T u) { return u and (static_cast<u64>(u) & static_cast<u64>(u - 1)) == 0; }
template<typename T> constexpr T ceil2(const T u) { return static_cast<T>(1) << clog(u); }
template<typename T> constexpr T floor2(const T u) { return u == 0 ? static_cast<T>(0) : static_cast<T>(1) << (log2p1(u) - 1); }
template<typename T> constexpr bool btest(const T mask, const usize ind) { return static_cast<bool>((static_cast<u64>(mask) >> ind) & static_cast<u64>(1)); }
template<typename T> void bset(T& mask, const usize ind) { mask |= (static_cast<T>(1) << ind); }
template<typename T> void breset(T& mask, const usize ind) { mask &= ~(static_cast<T>(1) << ind); }
template<typename T> void bflip(T& mask, const usize ind) { mask ^= (static_cast<T>(1) << ind); }
template<typename T> void bset(T& mask, const usize ind, const bool b) { (b ? bset(mask, ind) : breset(mask, ind)); }
template<typename T> constexpr T bcut(const T mask, const usize ind) { return ind == 0 ? static_cast<T>(0) : static_cast<T>((static_cast<u64>(mask) << (64 - ind)) >> (64 - ind)); }
template<typename T> bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template<typename T> bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
constexpr unsigned int mod = 1000000007;
template<typename T> constexpr T inf_v = std::numeric_limits<T>::max() / 4;
template<typename Real> constexpr Real pi_v = Real{3.141592653589793238462643383279502884};
auto mfp = [](auto&& f) { return [=](auto&&... args) { return f(f, std::forward<decltype(args)>(args)...); }; };
template<typename T>
T in()
{
T v;
return std::cin >> v, v;
}
template<typename T, typename Uint, usize n, usize i>
T in_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type) { return in<T>(); }
template<typename T, typename Uint, usize n, usize i>
auto in_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type& szs)
{
const usize s = (usize)szs[i];
std::vector<decltype(in_v<T, Uint, n, i + 1>(szs))> ans(s);
for (usize j = 0; j < s; j++) { ans[j] = in_v<T, Uint, n, i + 1>(szs); }
return ans;
}
template<typename T, typename Uint, usize n>
auto in_v(c_arr<Uint, n> szs) { return in_v<T, Uint, n, 0>(szs); }
template<typename... Types>
auto in_t() { return std::tuple<std::decay_t<Types>...>{in<Types>()...}; }
struct io_init
{
io_init()
{
std::cin.tie(nullptr), std::ios::sync_with_stdio(false);
std::cout << std::fixed << std::setprecision(20);
}
void clear()
{
std::cin.tie(), std::ios::sync_with_stdio(true);
}
} io_setting;
int out() { return 0; }
template<typename T>
int out(const T& v) { return std::cout << v, 0; }
template<typename T>
int out(const std::vector<T>& v)
{
for (usize i = 0; i < v.size(); i++) {
if (i > 0) { std::cout << ' '; }
out(v[i]);
}
return 0;
}
template<typename T1, typename T2>
int out(const std::pair<T1, T2>& v) { return out(v.first), std::cout << ' ', out(v.second), 0; }
template<typename T, typename... Args>
int out(const T& v, const Args... args) { return out(v), std::cout << ' ', out(args...), 0; }
template<typename... Args>
int outln(const Args... args) { return out(args...), std::cout << '\n', 0; }
template<typename... Args>
int outel(const Args... args) { return out(args...), std::cout << std::endl, 0; }
# define SHOW(...) static_cast<void>(0)
constexpr ull TEN(const usize n) { return n == 0 ? 1ULL : TEN(n - 1) * 10ULL; }
template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type, const T& v = T{}) { return v; }
template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type szs, const T& v = T{})
{
const usize s = (usize)szs[i];
return std::vector<decltype(make_v<T, Uint, n, i + 1>(szs, v))>(s, make_v<T, Uint, n, i + 1>(szs, v));
}
template<typename T, typename Uint, usize n>
auto make_v(c_arr<Uint, n> szs, const T& t = T{}) { return make_v<T, Uint, n, 0>(szs, t); }
template<typename T> T gcd(const T& a, const T& b) { return a < 0 ? gcd(-a, b) : b < 0 ? gcd(a, -b) : (a > b ? gcd(b, a) : a == 0 ? b : gcd(b % a, a)); }
template<typename T> T lcm(const T& a, const T& b) { return a / gcd(a, b) * b; }
class xoshiro
{
public:
using result_type = uint32_t;
static constexpr result_type min() { return std::numeric_limits<result_type>::min(); }
static constexpr result_type max() { return std::numeric_limits<result_type>::max(); }
xoshiro() : xoshiro(std::random_device{}()) {}
xoshiro(uint64_t seed)
{
uint64_t z = 0;
for (int i = 0; i < 4; i++) { z = (seed += 0x9e3779b97f4a7c15), z = (z ^ (z >> 33)) * 0x62A9D9ED799705F5, z = (z ^ (z >> 28)) * 0xCB24D0A5C88C35B3, s[i] = static_cast<result_type>(z >> 32); }
}
result_type operator()()
{
const result_type result = rotl(s[1] * 5, 7) * 9, t = s[1] << 9;
return s[2] ^= s[0], s[3] ^= s[1], s[1] ^= s[2], s[0] ^= s[3], s[2] ^= t, s[3] = rotl(s[3], 11), result;
}
void discard(const usize rep)
{
for (usize i = 0; i < rep; i++) { (*this)(); }
}
private:
result_type s[4];
static result_type rotl(const result_type x, const int k) { return (x << k) | (x >> (32 - k)); }
};
class xoshiro_64
{
public:
using result_type = uint64_t;
static constexpr result_type min() { return std::numeric_limits<result_type>::min(); }
static constexpr result_type max() { return std::numeric_limits<result_type>::max(); }
xoshiro_64() : xoshiro_64(std::random_device{}()) {}
xoshiro_64(uint64_t seed)
{
uint64_t z = 0;
for (int i = 0; i < 4; i++) { z = (seed += 0x9e3779b97f4a7c15), z = (z ^ (z >> 30)) * 0xbf58476d1ce4e5b9, z = (z ^ (z >> 27)) * 0x94d049bb133111eb, s[i] = static_cast<result_type>(z ^ (z >> 31)); }
}
result_type operator()()
{
const result_type result = rotl(s[1] * 5, 7) * 9, t = s[1] << 17;
return s[2] ^= s[0], s[3] ^= s[1], s[1] ^= s[2], s[0] ^= s[3], s[2] ^= t, s[3] = rotl(s[3], 45), result;
}
void discard(const usize rep)
{
for (usize i = 0; i < rep; i++) { (*this)(); }
}
private:
result_type s[4];
static result_type rotl(const result_type x, const int k) { return (x << k) | (x >> (64 - k)); }
};
template<typename Rng>
class rng_base
{
public:
using rng_type = Rng;
using result_type = typename rng_type::result_type;
static constexpr result_type min() { return rng_type::min(); }
static constexpr result_type max() { return rng_type::max(); }
rng_base() : rng_base(std::random_device{}()) {}
rng_base(const u64 seed) : rng(seed) {}
~rng_base() = default;
result_type operator()(const result_type max = std::numeric_limits<result_type>::max())
{
if (max == std::numeric_limits<result_type>::max()) { return static_cast<result_type>(rng()); }
if (ispow2(max + 1)) { return static_cast<result_type>(rng() & max); }
const result_type mask = static_cast<result_type>(ceil2(static_cast<u64>(max + 1))) - 1;
while (true) {
const result_type ans = static_cast<result_type>(rng() & mask);
if (ans <= max) { return ans; }
}
}
template<typename Int = result_type>
Int operator()(const Int min, const Int max) { return min + (Int)(*this)(max - min); }
operator bool() { return (bool)(*this)(0, 1); }
template<typename Int> std::pair<Int, Int> pair(const Int min, const Int max) { return std::pair<Int, Int>{*this(min, max), *this(min, max)}; }
template<typename Int>
std::vector<Int> vec(const usize n, const Int min, const Int max)
{
std::vector<Int> v(n);
for (usize i = 0; i < n; i++) { v[i] = (*this)(min, max); }
return v;
}
std::vector<usize> perm(const usize n)
{
std::vector<usize> ans(n);
std::iota(ans.begin(), ans.end(), 0UL);
std::shuffle(ans.begin(), ans.end(), rng);
return ans;
}
private:
Rng rng;
};
using rng_mt = rng_base<std::mt19937>;
using rng_mt64 = rng_base<std::mt19937_64>;
using rng_xoshiro = rng_base<xoshiro>;
using rng_xoshiro64 = rng_base<xoshiro_64>;
rng_mt g_rng_mt;
rng_mt64 g_rng_mt64;
rng_xoshiro g_rng_xo;
rng_xoshiro64 g_rng_xo64;
template<typename T, typename V>
inline bool miller_rabin(const T& n, const std::vector<T>& as)
{
auto pow = [&](auto&& self, const V& a, const T k) -> V {
if (k == 0) { return 1; }
if (k % 2 == 0) {
return self(self, (a * a) % V(n), k / 2);
} else {
return (self(self, a, k - 1) * a) % V(n);
}
};
T d = n - 1;
for (; (d & 1) == 0; d >>= 1) {}
for (const T& a : as) {
if (n <= a) { break; }
T s = d;
V x = pow(pow, a, s);
while (x != 1 and x != n - 1 and s != n - 1) {
(x *= x) %= V(n);
s *= 2;
}
if (x != n - 1 and s % 2 == 0) { return false; }
}
return true;
}
template<typename T>
inline bool is_prime(const T& n, const usize trial)
{
if (n % 2 == 0) { return n == 2; }
std::vector<T> as(trial);
for (usize i = 0; i < trial; i++) { as[i] = static_cast<T>(g_rng_xo64(T{2}, n - 2)); }
return miller_rabin<T, T>(n, as);
}
inline bool is_prime(const ull n)
{
if (n % 2 == 0) { return n == 2; }
if (n < (1ULL << 32)) {
return miller_rabin<uint, ull>((uint)n, std::vector<uint>{2, 7, 61});
} else {
return miller_rabin<ull, __uint128_t>(n, std::vector<ull>{2, 325, 9375, 28178, 450775, 9780504});
}
}
template<typename T, typename V = T>
T pollard_rho(const T n)
{
if (n % 2 == 0) { return 2; }
if (is_prime(n)) { return n; }
for (T c = 1; c < n; c++) {
if (c == n - 2) { continue; }
auto f = [&](const T x) -> T { return T((V(x) * V(x) + V(c)) % V(n)); };
T x = 2, y = 2, d = 1;
while (d == 1) {
x = f(x), y = f(f(y));
d = gcd(std::max(x, y) - std::min(x, y), n);
}
if (d != n) { return d; }
}
return n;
}
std::map<ull, usize> prime_factors(const ull n)
{
std::map<ull, usize> ans;
auto factor = [&](auto&& self, const ull n) -> void {
if (n == 1) { return; }
const ull p = (n < (1ULL << 32)) ? (ull)pollard_rho<uint, ull>((uint)n) : pollard_rho<ull, __uint128_t>(n);
if (p == n) {
ans[p]++;
return;
}
self(self, p);
self(self, n / p);
};
factor(factor, n);
return ans;
}
template<typename T>
constexpr std::pair<T, T> extgcd(const T a, const T b)
{
if (b == 0) { return std::pair<T, T>{1, 0}; }
const auto g = gcd(a, b), da = std::abs(b) / g;
const auto p = extgcd(b, a % b);
const auto x = (da + p.second % da) % da, y = (g - a * x) / b;
return {x, y};
}
template<typename T>
constexpr T inverse(const T a, const T mod) { return extgcd(a, mod).first; }
template<uint mod_value, bool dynamic = false>
class modint_base
{
public:
template<typename UInt = uint>
static std::enable_if_t<dynamic, const UInt> mod() { return mod_ref(); }
template<typename UInt = uint>
static constexpr std::enable_if_t<not dynamic, const UInt> mod() { return mod_value; }
template<typename UInt = uint>
static void set_mod(const std::enable_if_t<dynamic, const UInt> mod) { mod_ref() = mod, inv_ref() = {1, 1}; }
modint_base() : v{0} {}
modint_base(const ll val) : v{norm(static_cast<uint>(val % static_cast<ll>(mod()) + static_cast<ll>(mod())))} {}
modint_base(const modint_base& n) : v{n()} {}
explicit operator bool() const { return v != 0; }
bool operator!() const { return not static_cast<bool>(*this); }
modint_base& operator=(const modint_base& m) { return v = m(), (*this); }
modint_base& operator=(const ll val) { return v = norm(uint(val % static_cast<ll>(mod()) + static_cast<ll>(mod()))), (*this); }
friend modint_base operator+(const modint_base& m) { return m; }
friend modint_base operator-(const modint_base& m) { return make(norm(mod() - m.v)); }
friend modint_base operator+(const modint_base& m1, const modint_base& m2) { return make(norm(m1.v + m2.v)); }
friend modint_base operator-(const modint_base& m1, const modint_base& m2) { return make(norm(m1.v + mod() - m2.v)); }
friend modint_base operator*(const modint_base& m1, const modint_base& m2) { return make(static_cast<uint>(static_cast<ll>(m1.v) * static_cast<ll>(m2.v) % static_cast<ll>(mod()))); }
friend modint_base operator/(const modint_base& m1, const modint_base& m2) { return m1 * inv(m2.v); }
friend modint_base operator+(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) + val}; }
friend modint_base operator-(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) - val}; }
friend modint_base operator*(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) * (val % static_cast<ll>(mod()))}; }
friend modint_base operator/(const modint_base& m, const ll val) { return modint_base{static_cast<ll>(m.v) * inv(val)}; }
friend modint_base operator+(const ll val, const modint_base& m) { return modint_base{static_cast<ll>(m.v) + val}; }
friend modint_base operator-(const ll val, const modint_base& m) { return modint_base{-static_cast<ll>(m.v) + val}; }
friend modint_base operator*(const ll val, const modint_base& m) { return modint_base{static_cast<ll>(m.v) * (val % static_cast<ll>(mod()))}; }
friend modint_base operator/(const ll val, const modint_base& m) { return modint_base{val * inv(static_cast<ll>(m.v))}; }
friend modint_base& operator+=(modint_base& m1, const modint_base& m2) { return m1 = m1 + m2; }
friend modint_base& operator-=(modint_base& m1, const modint_base& m2) { return m1 = m1 - m2; }
friend modint_base& operator*=(modint_base& m1, const modint_base& m2) { return m1 = m1 * m2; }
friend modint_base& operator/=(modint_base& m1, const modint_base& m2) { return m1 = m1 / m2; }
friend modint_base& operator+=(modint_base& m, const ll val) { return m = m + val; }
friend modint_base& operator-=(modint_base& m, const ll val) { return m = m - val; }
friend modint_base& operator*=(modint_base& m, const ll val) { return m = m * val; }
friend modint_base& operator/=(modint_base& m, const ll val) { return m = m / val; }
friend modint_base operator^(const modint_base& m, const ll n) { return power(m.v, n); }
friend modint_base& operator^=(modint_base& m, const ll n) { return m = m ^ n; }
friend bool operator==(const modint_base& m1, const modint_base& m2) { return m1.v == m2.v; }
friend bool operator!=(const modint_base& m1, const modint_base& m2) { return not(m1 == m2); }
friend bool operator==(const modint_base& m, const ll val) { return m.v == norm(static_cast<uint>(static_cast<ll>(mod()) + val % static_cast<ll>(mod()))); }
friend bool operator!=(const modint_base& m, const ll val) { return not(m == val); }
friend bool operator==(const ll val, const modint_base& m) { return m.v == norm(static_cast<uint>(static_cast<ll>(mod()) + val % static_cast<ll>(mod()))); }
friend bool operator!=(const ll val, const modint_base& m) { return not(m == val); }
friend bool operator<(const modint_base& m1, const modint_base& m2) { return m1() < m2(); }
friend std::istream& operator>>(std::istream& is, modint_base& m)
{
ll v;
return is >> v, m = v, is;
}
friend std::ostream& operator<<(std::ostream& os, const modint_base& m) { return os << m(); }
uint operator()() const { return v; }
static modint_base small_inv(const usize n)
{
auto& in = inv_ref();
if (n < in.size()) { return in[n]; }
for (usize i = in.size(); i <= n; i++) { in.push_back(-in[modint_base::mod() % i] * (modint_base::mod() / i)); }
return in.back();
}
std::pair<ll, ll> quad() const
{
const auto ans = quad_r(v, mod());
ll x = std::get<0>(ans), y = std::get<1>(ans);
if (y < 0) { x = -x, y = -y; }
return {x, y};
}
private:
static std::tuple<ll, ll, ll> quad_r(const ll r, const ll p) // r = x/y (mod p), (x,y,z) s.t. x=yr+pz
{
if (std::abs(r) <= 1000) { return {r, 1, 0}; }
ll nr = p % r, q = p / r;
if (nr * 2LL >= r) { nr -= r, q++; }
if (nr * 2LL <= -r) { nr += r, q--; }
const auto sub = quad_r(nr, r);
const ll x = std::get<0>(sub), z = std::get<1>(sub), y = std::get<2>(sub);
return {x, y - q * z, z};
}
template<typename UInt = uint>
static std::enable_if_t<dynamic, UInt&> mod_ref()
{
static UInt mod = 0;
return mod;
}
static uint norm(const uint x) { return x < mod() ? x : x - mod(); }
static modint_base make(const uint x)
{
modint_base m;
return m.v = x, m;
}
static modint_base power(modint_base x, ull n)
{
modint_base ans = 1;
for (; n; n >>= 1, x *= x) {
if (n & 1) { ans *= x; }
}
return ans;
}
static modint_base inv(const ll v) { return v <= 2000000 ? small_inv(static_cast<usize>(v)) : modint_base{inverse(v, static_cast<ll>(mod()))}; }
static std::vector<modint_base>& inv_ref()
{
static std::vector<modint_base> in{1, 1};
return in;
}
uint v;
};
template<uint mod>
using modint = modint_base<mod, false>;
template<uint id>
using dynamic_modint = modint_base<id, true>;
template<typename Ring>
class discrete_log
{
public:
discrete_log(const Ring x, const ull period, const ull query) : x{x}, period{period}
{
for (; bs * bs * query < period; bs++) {}
for (ull i = 0; i * bs < period; i++) { giant[x ^ (i * bs)] = i * bs; }
}
ull operator()(Ring y)
{
for (ull i = 0; i < bs; i++) {
if (giant.count(y)) { return (giant[y] + period - i) % period; }
y = y * x;
}
return period;
}
private:
const Ring x;
ull period;
ull bs = 1;
std::map<Ring, ull> giant;
};
template<typename T>
std::pair<T, T> crt(const std::pair<T, T>& a1, const std::pair<T, T>& a2)
{
using P = std::pair<T, T>;
T r1 = a1.first, m1 = a1.second, r2 = a2.first, m2 = a2.second;
const T g = gcd(m1, m2);
if (r1 % g != r2 % g) { return P{0, 0}; }
const T m = m1 / g * m2;
if (r1 == r2) { return {r1, m}; }
const auto k1 = extgcd(m1, m2).first * ((r2 - r1) / g) % (m2 / g);
return P{(m + (m1 * k1 % m) + r1) % m, m};
}
template<typename T, typename InIt>
std::pair<T, T> crt(const InIt first, const InIt last)
{
using P = std::pair<T, T>;
return std::accumulate(first, last, P{0, 1}, [](const P& a1, const P& a2) -> P { return crt(a1, a2); });
}
int main()
{
using mint = dynamic_modint<0>;
const auto T = in<int>();
for (int t = 0; t < T; t++) {
const auto p = in<uint>();
const auto k = in<uint>();
mint::set_mod(p);
const auto a = in<mint>();
const auto fs = prime_factors(p - 1);
mint g = 2;
for (;; g += 1) {
bool ok = true;
for (const auto& f : fs) {
const uint q = p / f.first;
if ((g ^ q) == 1) {
ok = false;
break;
}
}
if (ok) { break; }
}
SHOW(g);
discrete_log<mint> dlog(g, p - 1, 1);
const ull l = dlog(a); // y = l (mod p-1)
SHOW(l);
if ((g ^ l) != a) {
outln(-1);
continue;
}
using pll = std::pair<ll, ll>;
const auto y = crt<ll>(pll{l, p - 1}, pll{0LL, k});
SHOW(y);
const auto z = y.first / k;
const auto ans = g ^ z;
if ((ans ^ k) == a) {
outln(ans);
} else {
outln(-1);
}
}
return 0;
}