#include using namespace std; #if __has_include() #include using mint = atcoder::modint1000000007; istream& operator>>(istream& is, mint& a) { int t; is >> t; a = t; return is; } ostream& operator<<(ostream& os, mint a) { return os << a.val(); } #endif #ifdef DEBUG #define _GLIBCXX_DEBUG #else #pragma GCC target("avx2") #pragma GCC optimize("Ofast,unroll-loops") #define cerr if (false) cerr #undef assert #define assert(...) void(0) #undef endl #define endl '\n' #endif #define overload3(a, b, c, name, ...) name #define rep1(n) for (int i = 0; i < n; i++) #define rep2(i, n) for (int i = 0; i < n; i++) #define rep3(i, a, b) for (int i = a; i < b; i++) #define rep(...) overload3(__VA_ARGS__, rep3, rep2, rep1)(__VA_ARGS__) #define per1(n) for (int i = n - 1; i >= 0; i--) #define per2(i, n) for (int i = n - 1; i >= 0; i--) #define per3(i, a, b) for (int i = b - 1; i >= (a); i--) #define per(...) overload3(__VA_ARGS__, per3, per2, per1)(__VA_ARGS__) #define ALL(a) a.begin(), a.end() #define vec vector #undef long #define long long long template ostream& operator<<(ostream& os, vector a) { const int n = a.size(); rep(i, n) os << a[i] << " \n"[i + 1 == n]; return os; } template ostream& operator<<(ostream& os, array a) { rep(i, n) os << a[i] << " \n"[i + 1 == n]; return os; } template istream& operator>>(istream& is, vector& a) { for (T& i : a) is >> i; return is; } template bool chmin(T& x, T y) { if (x > y) { x = y; return true; } return false; } template bool chmax(T& x, T y) { if (x < y) { x = y; return true; } return false; } template void operator++(vector& a) { for (T& i : a) ++i; } template void operator--(vector& a) { for (T& i : a) --i; } template void operator++(vector& a, int) { for (T& i : a) i++; } template void operator--(vector& a, int) { for (T& i : a) i--; } void solve() { int n; cin >> n; mint ans = 1; while (n--) { mint p;int e; cin >> p >> e; mint m1 = p.pow(2 + e) - e * p - 2 * p + e + 1; mint m2 = (p - 1) * (p - 1); ans *= m1 / m2; } cout << ans << endl; } int main() { srand((unsigned)time(NULL)); cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(40); int t = 1; // cin >> t; while (t--) solve(); return 0; }