#ifndef LOCAL #define FAST_IO #endif #define INT128 // ============ #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 i32 = signed int; using i64 = signed long long; 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; } template Vec> runlength(const Vec &a) { if (a.empty()) { return Vec>(); } Vec> ret; i32 prv = 0; REP(i, 1, a.size()) { if (a[i - 1] != a[i]) { ret.emplace_back(prv, i, a[i - 1]); prv = i; } } ret.emplace_back(prv, (i32)a.size(), a.back()); return ret; } #ifdef INT128 using u128 = __uint128_t; using i128 = __int128_t; 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; } #endif [[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 // ============ 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); } } // ============ // count (x, y) s.t. a * x + b * y = k and lw <= x <= hi i64 count_ans(i64 a, i64 b, i64 k, i64 lw, i64 hi) { if (lw > hi) { return 0; } i64 g = gcd(a, b); if (k % g != 0) { return 0; } a /= g; b /= g; k /= g; if (b < 0) { a *= -1; b *= -1; k *= -1; } // a * x + b * y = k // a * x = k (mod b) // x = k * inv(a) (mod b) i64 x = safe_mod(atcoder::inv_mod(a, b) * k, b); lw -= x; hi -= x; return floor_div(hi, b) - floor_div(lw - 1, b); } i64 solve(i64 m, i64 a, i64 b, i64 k) { if (k > a) { return 0; } if (k == a) { i64 as = m / a; i64 bs = as * a / b; i64 ls = as * a / lcm(a, b); i64 ans = as - 1 - (bs - ls); return ans; } i64 ans = count_ans(-a, b, k, 1, floor_div(m / b * b - k, a)) + count_ans(a, -b, k, ceil_div(b + k, a), m / a); return ans; } int main() { i32 t; cin >> t; while (t--) { i64 m, a, b, k; cin >> m >> a >> b >> k; cout << solve(m, a, b, k) << '\n'; } }