#define _USE_MATH_DEFINES #include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define MT make_tuple #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)< >(b,vector(c,d)) #define vvv(a,b,c,d,e) vector > >(b,vv(a,c,d,e)) using ll = long long; using pii = pair; using vi = vector; using vll = vector; template class ModInt { public: ModInt() :value(0) {} ModInt(long long val) :value((int)(val<0 ? MOD + val%MOD : val%MOD)) { } ModInt& operator+=(ModInt that) { value = value + that.value; if (value >= MOD)value -= MOD; return *this; } ModInt& operator-=(ModInt that) { value -= that.value; if (value<0)value += MOD; return *this; } ModInt& operator*=(ModInt that) { value = (int)((long long)value * that.value % MOD); return *this; } ModInt &operator/=(ModInt that) { return *this *= that.inverse(); } ModInt operator+(ModInt that) const { return ModInt(*this) += that; } ModInt operator-(ModInt that) const { return ModInt(*this) -= that; } ModInt operator*(ModInt that) const { return ModInt(*this) *= that; } ModInt operator/(ModInt that) const { return ModInt(*this) /= that; } ModInt pow(long long k) const { if (value == 0)return 0; ModInt n = *this, res = 1; while (k) { if (k & 1)res *= n; n *= n; k >>= 1; } return res; } ModInt inverse() const { long long a = value, b = MOD, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } return ModInt(u); } int toi() const { return value; } private: int value; }; typedef ModInt<1000000007> mint; ostream& operator<<(ostream& os, const mint& x) { os << x.toi(); return os; } vector sieveFlags(int n) { vector f(n + 1); for (int i = 3; i <= n; i += 2)f[i] = true; for (int i = 3; (long long)i*i <= n; i += 2) { if (f[i])for (int j = i * 3; j <= n; j += i)f[j] = false; } if (n >= 2)f[2] = true; return f; } vector enumMobius(const vector &sf) { int n = (int)sf.size(); vector res(n, 1); for (int i = 1; i < n; ++i)if (sf[i]) { for (int j = i; j < n; j += i) { res[j] *= -1; } long long power = (long long)i*i; for (long long j = power; j < n; j += power) { res[j] = 0; } } return res; } vector enumTotient(int n) { vector sf = sieveFlags(n); vector res(n + 1); vector mobius = enumMobius(sf); for (int i = 1; i <= n; ++i) { int mob = mobius[i]; if (mob == 0)continue; for (int j = i, k = 1; j <= n; j += i, ++k) { res[j] += mob*k; } } return res; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(20); int N, M; cin >> N >> M; mint ans, A = 1; for (int i = 2; i <= N - 2; ++i)A *= i; N /= M; vi t = enumTotient(N); for (int i = 2; i <= N; ++i) { ans += A * 2 * t[i]; } cout << ans << endl; }