#include #include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; template vector> vec2d(int n, int m, T v){ return vector>(n, vector(m, v)); } template vector>> vec3d(int n, int m, int k, T v){ return vector>>(n, vector>(m, vector(k, v))); } template void print_vector(vector v, char delimiter=' '){ if(v.empty()) { cout << endl; return; } for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter; cout << v.back() << endl; } const ll MOD = 1000000007; class ModInt{ public: ll v; ModInt(ll _v = 0){ if(_v < 0) _v = (_v%MOD)+MOD; if(_v >= MOD) _v %= MOD; v = _v; } ModInt operator+(ll n){ return ModInt((v+n)%MOD); } ModInt operator-(ll n){ return ModInt((v-n+MOD)%MOD); } ModInt operator*(ll n){ if(n >= MOD) n %= MOD; return ModInt((v*n)%MOD); } ModInt operator/(ll n){ return ModInt((ModInt(n).inv()*v).v%MOD); } ModInt &operator+=(ll n){ v = (v+n)%MOD; return *this; } ModInt &operator-=(ll n){ v = (v-n+MOD)%MOD; return *this; } ModInt &operator*=(ll n){ v = (v*n+MOD)%MOD; return *this; } ModInt operator+(ModInt n){ return ModInt((v+n.v)%MOD); } ModInt operator-(ModInt n){ return ModInt((v-n.v+MOD)%MOD); } ModInt operator*(ModInt n){ return ModInt((v*n.v)%MOD); } ModInt operator/(ModInt n){ return ModInt((n.inv()*v).v%MOD); } ModInt &operator+=(ModInt n){ v = (v+n.v)%MOD; return *this; } ModInt &operator-=(ModInt n){ v = (v-n.v+MOD)%MOD; return *this; } ModInt &operator*=(ModInt n){ v = (v*n.v)%MOD; return *this; } bool operator==(ModInt n){ return v == n.v; } bool operator!=(ModInt n){ return v != n.v; } ModInt &operator=(ll n){ v = n%MOD; return *this; } ModInt inv(){ if(v == 1) return ModInt(1); else return ModInt(MOD-ModInt(MOD%v).inv().v*(MOD/v)%MOD); } }; ostream& operator<<(ostream& os, const ModInt& m){ os << m.v; return os; } istream & operator >> (istream &in, ModInt &m){ in >> m.v; return in; } ModInt pow(ModInt a, ll n) { assert(n >= 0); ModInt ans = 1; while (n > 0) { if (n&1) ans = ans*a; a = a*a; n >>= 1; } return ans; } struct UnionFind { vector data; UnionFind(int size) : data(size, -1) {} bool unionSet(int x, int y) { x = root(x); y = root(y); if (x != y) { if (data[y] < data[x]) swap(x, y); data[x] += data[y]; data[y] = x; } return x != y; } bool findSet(int x, int y) { return root(x) == root(y); } int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); } int size(int x) { return -data[root(x)]; } }; template struct matrix{ int n, m; vector> dat; matrix(int n_, int m_){ n = n_; m = m_; for(int i = 0; i < n; i++){ dat.push_back(vector(m)); } } matrix(int n, int m, T val): n(n), m(m){ for(int i = 0; i < n; i++){ dat.push_back(vector(m, val)); } } matrix(int n, int m, vector> dat): n(n), m(m), dat(dat){ assert((int)dat.size() == n); for(int i = 0; i < n; i++) assert(dat[i].size() == m); } vector& operator[](int x) { return dat[x]; } }; template bool prod(matrix a, matrix b, matrix &ans){ assert(a.m == b.n); for(int i = 0; i < a.n; i++){ for(int j = 0; j < b.m; j++){ ans.dat[i][j] = 0; for(int k = 0; k < b.n; k++){ ans.dat[i][j] += (a.dat[i][k]*b.dat[k][j]); } } } return true; } template void copy_mat(matrix a, matrix &b){ assert(a.n == b.n); assert(a.m == b.m); for(int i = 0; i < a.n; i++){ for(int j = 0; j < a.m; j++){ b.dat[i][j] = a.dat[i][j]; } } } template void pow_mat(matrix a, ll n, matrix &ans){ assert(n < ((ll)1<<61)); matrix buf(a.n, a.n); matrix tmp(a.n, a.n); copy_mat(a, tmp); for(int i = 0; i < a.n; i++) { for(int j = 0; j < a.n; j++){ ans.dat[i][j] = 0; } ans.dat[i][i] = 1; } while (n > 0) { if (n&1) { prod(tmp, ans, buf); copy_mat(buf, ans); } prod(tmp, tmp, buf); copy_mat(buf, tmp); n >>= 1; } } template void print_mat(matrix a){ for(int i = 0; i < a.n; i++){ for(int j = 0; j < a.m; j++){ cout << a.dat[i][j] << ' '; } cout << endl; } } template ostream& operator<<(ostream& os, const matrix& m){ print_mat(m); return os; } // x^0 + x^1 + ... + x^n-1 ModInt sum_pow(ModInt x, ll n){ matrix m(2, 2); m.dat[0][0] = x; m.dat[0][1] = 0; m.dat[1][0] = 1; m.dat[1][1] = 1; matrix v(2,1); v.dat[0][0] = 1; v.dat[1][0] = 0; matrix p(2, 2); pow_mat(m, n, p); matrix p_sum(2, 1); prod(p, v, p_sum); return p_sum.dat[1][0]; } using mint = ModInt; int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; int l; cin >> l; mint ans = 1; for(int i = 0; i < l; i++){ int p, e; cin >> p >> e; ans *= (sum_pow(mint(p), e+2)-e-2)/(p-1); } cout << ans << endl; }