#pragma GCC optimize ("O3") #include "bits/stdc++.h" using namespace std; using ll = long long int; #define debugos cout #define debug(v) {printf("L%d %s > ",__LINE__,#v);debugos<<(v)< ",__LINE__,#v);for(auto e:(v)){debugos< ",__LINE__,#m);for(int x=0;x<(w);x++){debugos<<(m)[x]<<" ";}debugos<\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){debugos<<(m)[y][x]<<" ";}debugos<::type();(cnt)<(l);++(cnt)) #define rrepeat(cnt,l) for(auto cnt=(l)-1;0<=(cnt);--(cnt)) #define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt)) #define diterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);--(cnt)) const ll MD = 1000000007ll; const long double PI = 3.1415926535897932384626433832795L; inline void assert_call(bool assertion, function f) { if (!assertion) { cerr << "assertion fault:" << endl; f(); abort(); } } template inline ostream& operator <<(ostream &o, const pair p) { o << '(' << p.first << ':' << p.second << ')'; return o; } template inline ostream& _ostream_vecprint(ostream& os, const Vec& a) { os << '['; for (const auto& e : a) os << ' ' << e << ' '; os << ']'; return os; } template inline ostream& operator<<(ostream& o, const vector& v) { return _ostream_vecprint(o, v); } template inline ostream& operator<<(ostream& o, const array& v) { return _ostream_vecprint(o, v); } template inline T& chmax(T& to, const T& val) { return to = max(to, val); } template inline T& chmin(T& to, const T& val) { return to = min(to, val); } void bye(string s, int code = 0) { cout << s << endl; exit(code); } mt19937_64 randdev(8901016); template::value>::type* = nullptr> inline T rand(T l, T h, Random& rand = randdev) { return uniform_int_distribution(l, h)(rand); } template::value>::type* = nullptr> inline T rand(T l, T h, Random& rand = randdev) { return uniform_real_distribution(l, h)(rand); } #if defined(_WIN32) || defined(_WIN64) #define getc_x _getc_nolock #define putc_x _putc_nolock #elif defined(__GNUC__) #define getc_x getc_unlocked #define putc_x putc_unlocked #else #define getc_x getc #define putc_x putc #endif #define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E) class MaiScanner { FILE* fp_; public: inline MaiScanner(FILE* fp):fp_(fp){} template void input_integer(T& var) noexcept { var = 0; T sign = 1; int cc = getc_x(fp_); for (; cc < '0' || '9' < cc; cc = getc_x(fp_)) if (cc == '-') sign = -1; for (; '0' <= cc && cc <= '9'; cc = getc_x(fp_)) var = (var << 3) + (var << 1) + cc - '0'; var = var * sign; } inline int c() noexcept { return getc_x(fp_); } inline MaiScanner& operator>>(int& var) noexcept { input_integer(var); return *this; } inline MaiScanner& operator>>(long long& var) noexcept { input_integer(var); return *this; } inline MaiScanner& operator>>(string& var) { int cc = getc_x(fp_); for (; !isvisiblechar(cc); cc = getc_x(fp_)); for (; isvisiblechar(cc); cc = getc_x(fp_)) var.push_back(cc); return *this; } template inline void in(IT begin, IT end) { for (auto it = begin; it != end; ++it) *this >> *it; } }; class MaiPrinter { FILE* fp_; public: inline MaiPrinter(FILE* fp):fp_(fp){} template void output_integer(T var) noexcept { if (var == 0) { putc_x('0', fp_); return; } if (var < 0) putc_x('-', fp_), var = -var; char stack[32]; int stack_p = 0; while (var) stack[stack_p++] = '0' + (var % 10), var /= 10; while (stack_p) putc_x(stack[--stack_p], fp_); } inline MaiPrinter& operator<<(char c) noexcept { putc_x(c, fp_); return *this; } inline MaiPrinter& operator<<(int var) noexcept { output_integer(var); return *this; } inline MaiPrinter& operator<<(long long var) noexcept { output_integer(var); return *this; } inline MaiPrinter& operator<<(char* str_p) noexcept { while (*str_p) putc_x(*(str_p++), fp_); return *this; } inline MaiPrinter& operator<<(const string& str) { const char* p = str.c_str(); const char* l = p + str.size(); while (p < l) putc_x(*p++, fp_); return *this; } template void join(IT begin, IT end, char sep = ' ') { for (bool b = 0; begin != end; ++begin, b = 1) b ? *this << sep << *begin : *this << *begin; } }; MaiScanner scanner(stdin); MaiPrinter printer(stdout); template class Combinatorics { using value_type = long long; value_type fact_[MaxN + 1]; // value_type inv_[MaxN + 1]; // iranai public: value_type pow(value_type x, value_type p) { value_type y = 1; x = x % Mod; for (; 0 < p; p >>= 1) { if (p & 1) y = y * x % Mod; x = x * x % Mod; } return y; } Combinatorics() :fact_() { fact_[0] = 1; fact_[1] = 1; for (value_type n = 2; n <= MaxN; ++n) fact_[n] = (fact_[n - 1] * n) % Mod; // inv_[Max] := calculate; // iterate => inv_[i] = inv_[i+1] * (i+1) % MD; } inline value_type fact(int n) const { return fact_[n]; } inline value_type inv(value_type n) { return pow(n, MD - 2); } inline value_type nPr(value_type n, value_type r) { if (r < 0 || n < r) return 0; return fact_[n] * inv(fact_[n - r]) % MD; } inline value_type nCr(value_type n, value_type r) { if (n < r) return 0; return ((fact_[n] * inv(fact_[n - r]) % MD) * inv(fact_[r])) % MD; } inline value_type nHr(value_type n, value_type r) { if (n == 0 && r == 0) return 1; if (n == 0) return 0; return nCr(n - 1 + r, n - 1); } }; template class IsPrimeC { bool d_[Max + 1]; template static constexpr T cesqrt(T s) { double x = s / 2.0; double prev = 0.0; while (x != prev) { prev = x; x = (x + s / x) / 2.0; } return x; } public: constexpr IsPrimeC(): d_() { d_[0] = d_[1] = 1; int sqh = cesqrt(Max); for (int i = 2; i <= sqh; i++) { if (d_[i] == 0) { for (int j = i * i; j <= Max; j += i) { // i*i d_[j] = 1; } } } for (int i = 0; i <= Max; ++i) d_[i] = !d_[i]; } constexpr inline bool operator[](int x) const{return d_[x]; } }; template class PrimeListC { int d_[Max]; public: PrimeListC() : d_() { int n = 1; d_[0] = 2; for (int x = 3; n < Max; ++x) { bool f = true; for (int i = 0; d_[i] * d_[i] <= x; ++i) if (x / d_[i] * d_[i] == x) { f = false; break; } if (f) d_[n++] = x; } } inline int operator[](int x) const { return d_[x]; } template class iterator { const PrimeListC<_Max>& pl; int ptr = 0; public: constexpr iterator(const decltype(pl)& _pl, int _ptr = 0) :pl(_pl),ptr(_ptr) { } constexpr int operator*() const { return pl[ptr]; } constexpr iterator<_Max>& operator++() { ptr++; return *this; } // prefix constexpr inline bool operator!=(const iterator<_Max>& it) const { return ptr != it.ptr ? !(_Max < ptr && _Max < it.ptr) : false; } constexpr inline bool operator==(const iterator<_Max>& it) const { return ptr != it.ptr ? (_Max < ptr && _Max < it.ptr) : true; } }; constexpr PrimeListC::iterator begin() const { return PrimeListC::iterator(*this, 0); } constexpr PrimeListC::iterator end() const { return PrimeListC::iterator(*this, Max); } map division(ll number) const { map div; for (int i = 0; number > 1 && i < Max; ++i) { ll p = d_[i]; int c = 0; while (number / p * p == number) ++c, number /= p; if (c > 0) div[p] = c; } return div; } }; // PrimeListC<500010> P; Combinatorics<500010, MD> C; int N, K; // int main() { scanner >> N >> K; if (N == 1) bye("0"); // 分かりにくいです ll ans = 0; for (auto d1 : P) { if (d1*2 > N) break; for (auto d2 : P) { if (d2*2 > N) break; if (d1 > d2) continue; auto d = d1*d2; if (d1 == d2) d = d1; int n = N, k = K; if (n%d == 0 && k%d == 0) { n /= d; k /= d; ll v = C.nCr(n, k); if (d1 == d2) ans += v; else ans += MD-v; ans %= MD; // cout << d << ' ' << v << endl; } } } cout << ans << endl; return 0; }