#ifndef LOCAL #define FAST_IO #endif // ============ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define OVERRIDE(a, b, c, d, ...) d #define REP2(i, n) for (i32 i = 0; i < (i32) (n); ++i) #define REP3(i, m, n) for (i32 i = (i32) (m); i < (i32) (n); ++i) #define REP(...) OVERRIDE(__VA_ARGS__, REP3, REP2)(__VA_ARGS__) #define PER(i, n) for (i32 i = (i32) (n) - 1; i >= 0; --i) #define ALL(x) begin(x), end(x) using namespace std; using u32 = unsigned int; using u64 = unsigned long long; using u128 = __uint128_t; using i32 = signed int; using i64 = signed long long; using i128 = __int128_t; using f64 = double; using f80 = long double; template using Vec = vector; template bool chmin(T &x, const T &y) { if (x > y) { x = y; return true; } return false; } template bool chmax(T &x, const T &y) { if (x < y) { x = y; return true; } return false; } istream &operator>>(istream &is, i128 &x) { i64 v; is >> v; x = v; return is; } ostream &operator<<(ostream &os, i128 x) { os << (i64) x; return os; } istream &operator>>(istream &is, u128 &x) { u64 v; is >> v; x = v; return is; } ostream &operator<<(ostream &os, u128 x) { os << (u64) x; return os; } [[maybe_unused]] constexpr i32 INF = 1000000100; [[maybe_unused]] constexpr i64 INF64 = 3000000000000000100; struct SetUpIO { SetUpIO() { #ifdef FAST_IO ios::sync_with_stdio(false); cin.tie(nullptr); #endif cout << fixed << setprecision(15); } } set_up_io; // ============ #ifdef DEBUGF #else #define DBG(x) (void) 0 #endif // ============ #include #include #include // ============ constexpr bool is_prime(unsigned n) { if (n == 0 || n == 1) { return false; } for (unsigned i = 2; i * i <= n; ++i) { if (n % i == 0) { return false; } } return true; } constexpr unsigned mod_pow(unsigned x, unsigned y, unsigned mod) { unsigned ret = 1, self = x; while (y != 0) { if (y & 1) { ret = (unsigned) ((unsigned long long) ret * self % mod); } self = (unsigned) ((unsigned long long) self * self % mod); y /= 2; } return ret; } template constexpr unsigned primitive_root() { static_assert(is_prime(mod), "`mod` must be a prime number."); if (mod == 2) { return 1; } unsigned primes[32] = {}; int it = 0; { unsigned m = mod - 1; for (unsigned i = 2; i * i <= m; ++i) { if (m % i == 0) { primes[it++] = i; while (m % i == 0) { m /= i; } } } if (m != 1) { primes[it++] = m; } } for (unsigned i = 2; i < mod; ++i) { bool ok = true; for (int j = 0; j < it; ++j) { if (mod_pow(i, (mod - 1) / primes[j], mod) == 1) { ok = false; break; } } if (ok) return i; } return 0; } // y >= 1 template constexpr T safe_mod(T x, T y) { x %= y; if (x < 0) { x += y; } return x; } // y != 0 template constexpr T floor_div(T x, T y) { if (y < 0) { x *= -1; y *= -1; } if (x >= 0) { return x / y; } else { return -((-x + y - 1) / y); } } // y != 0 template constexpr T ceil_div(T x, T y) { if (y < 0) { x *= -1; y *= -1; } if (x >= 0) { return (x + y - 1) / y; } else { return -(-x / y); } } // ============ template class ModInt { static_assert(mod != 0, "`mod` must not be equal to 0."); static_assert( mod < (1u << 31), "`mod` must be less than (1u << 31) = 2147483648."); unsigned val; public: constexpr ModInt() : val(0) {} template > * = nullptr> constexpr ModInt(T x) : val((unsigned) ((long long) x % (long long) mod + (x < 0 ? mod : 0))) {} template > * = nullptr> constexpr ModInt(T x) : val((unsigned) (x % mod)) {} static constexpr ModInt raw(unsigned x) { ModInt ret; ret.val = x; return ret; } constexpr unsigned get_val() const { return val; } constexpr ModInt operator+() const { return *this; } constexpr ModInt operator-() const { return ModInt(0u) - *this; } constexpr ModInt &operator+=(const ModInt &rhs) { val += rhs.val; if (val >= mod) val -= mod; return *this; } constexpr ModInt &operator-=(const ModInt &rhs) { if (val < rhs.val) val += mod; val -= rhs.val; return *this; } constexpr ModInt &operator*=(const ModInt &rhs) { val = (unsigned long long)val * rhs.val % mod; return *this; } constexpr ModInt &operator/=(const ModInt &rhs) { val = (unsigned long long)val * rhs.inv().val % mod; return *this; } friend constexpr ModInt operator+(const ModInt &lhs, const ModInt &rhs) { return ModInt(lhs) += rhs; } friend constexpr ModInt operator-(const ModInt &lhs, const ModInt &rhs) { return ModInt(lhs) -= rhs; } friend constexpr ModInt operator*(const ModInt &lhs, const ModInt &rhs) { return ModInt(lhs) *= rhs; } friend constexpr ModInt operator/(const ModInt &lhs, const ModInt &rhs) { return ModInt(lhs) /= rhs; } constexpr ModInt pow(unsigned long long x) const { ModInt ret = ModInt::raw(1); ModInt self = *this; while (x != 0) { if (x & 1) ret *= self; self *= self; x >>= 1; } return ret; } constexpr ModInt inv() const { static_assert(is_prime(mod), "`mod` must be a prime number."); assert(val != 0); return this->pow(mod - 2); } friend std::istream &operator>>(std::istream &is, ModInt &x) { is >> x.val; x.val %= mod; return is; } friend std::ostream &operator<<(std::ostream &os, const ModInt &x) { os << x.val; return os; } friend bool operator==(const ModInt &lhs, const ModInt &rhs) { return lhs.val == rhs.val; } friend bool operator!=(const ModInt &lhs, const ModInt &rhs) { return lhs.val != rhs.val; } }; [[maybe_unused]] constexpr unsigned mod998244353 = 998244353; [[maybe_unused]] constexpr unsigned mod1000000007 = 1000000007; // ============ // ============ #include #include class LinearSieve { std::vector mpf; std::vector ps; public: LinearSieve(int n) : mpf(n + 1) { std::iota(mpf.begin(), mpf.end(), 0); for (int i = 2; i <= n; ++i) { if (mpf[i] == i) { ps.push_back(i); } for (int p : ps) { if (p > mpf[i] || i * p > n) { break; } mpf[p * i] = p; } } } int min_prime_factor(int n) const { assert(n >= 2 && n < (int) mpf.size()); return mpf[n]; } std::vector primes() const { return ps; } bool is_prime(int n) const { assert(n < (int) mpf.size()); return n >= 2 && mpf[n] == n; } std::vector> factorize(int n) const { assert(n > 0 && n < mpf.size()); std::vector> ret; while (n > 1) { int p = mpf[n]; int ex = 0; while (n % p == 0) { n /= p; ++ex; } ret.emplace_back(p, ex); } return ret; } }; // ============ using Mint = ModInt<998244353>; int main() { i32 n; cin >> n; Vec a(n); REP(i, n) { cin >> a[i]; } i32 mx = *max_element(ALL(a)); LinearSieve sieve(mx); Vec> divs(mx + 1); REP(i, 1, mx + 1) { for (i32 j = i; j <= mx; j += i) { divs[j].push_back(i); } } DBG(divs); Vec> prs(mx + 1); for (i32 p : sieve.primes()) { for (i32 j = p; j <= mx; j += p) { prs[j].push_back(p); } } Vec dp(mx + 1); REP(i, n) { Mint s(1); REP(bit, 1, 1 << prs[a[i]].size()) { i32 pr = 1; REP(j, prs[a[i]].size()) { if (bit & (1 << j)) { pr *= prs[a[i]][j]; } } Mint d = dp[pr]; if (__builtin_parity(bit)) { s += d; } else { s -= d; } } DBG(dp); DBG(s); for (i32 d : divs[a[i]]) { dp[d] += s; } DBG(dp); } cout << dp[1] << '\n'; }