#include <bits/stdc++.h>
using namespace std;
#include <atcoder/modint>
using namespace atcoder;
//using mint = modint998244353;
using mint = modint1000000007;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using tlll = tuple<ll, ll, ll>;
constexpr ll INF = 1LL << 60;
template<class T> bool chmin(T& a, T b) {if (a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T& a, T b) {if (a < b) {a = b; return true;} return false;}
ll safemod(ll A, ll M) {return (A % M + M) % M;}
ll divfloor(ll A, ll B) {if (B < 0) {return divfloor(-A, -B);} return (A - safemod(A, B)) / B;}
ll divceil(ll A, ll B) {if (B < 0) {return divceil(-A, -B);} return divfloor(A + B - 1, B);}
template<class T> void unique(vector<T> &V) {V.erase(unique(V.begin(), V.end()), V.end());}
template<class T> void sortunique(vector<T> &V) {sort(V.begin(), V.end()); V.erase(unique(V.begin(), V.end()), V.end());}
#define FINALANS(A) do {cout << (A) << '\n'; exit(0);} while (false)
template<class T> void printvec(vector<T> &V) {int N = V.size(); for (int i = 0; i < N; i++) cout << V[i] << (i == N - 1 ? '\n' : ' ');}
template<class T> void printvect(vector<T> &V) {for (auto v : V) cout << v << '\n';}
template<class T> void printvec2(vector<vector<T>> &V) {for (auto &v : V) printvec(v);}

mint sum0(mint a, int n) // sum[i = 0 .. n - 1] a^i
{
  if (a == 1)
    return n;
  return (1 - a.pow(n)) / (1 - a);
}

mint sum1(mint a, int n) // sum[i = 0 .. n - 1] ia^i
{
  if (a == 1)
    return mint(n) * (n - 1) / 2;
  return (sum0(a, n) - 1 - (n - 1) * a.pow(n)) / (1 - a);
}

int main()
{
  ll L;
  cin >> L;
  vector<ll> P(L), E(L);
  for (ll i = 0; i < L; i++)
  {
    cin >> P.at(i) >> E.at(i);
  }

  mint ans = 1;
  for (ll i = 0; i < L; i++)
  {
    ll p = P.at(i), e = E.at(i);
    mint tmp = (e + 1) * sum0(p, e + 1) - sum1(p, e + 1);
    ans *= tmp;
  }
  cout << ans.val() << endl;
}