#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep3(i, l, n) for (int i = l; i < (n); ++i)
#define sz(v) (int)v.size()
const int inf = 1e9 + 7;
const ll INF = 1e18;
#define abs(x) (x >= 0 ? x : -(x))
#define lb(v, x) (int)(lower_bound(all(v), x) - v.begin())
#define ub(v, x) (int)(upper_bound(all(v), x) - v.begin())
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { if (a < b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a, T b) { if (b == 0) return a; return gcd(b, a % b); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
template<typename T> T pow(T a, int b) { return b ? pow(a * a, b / 2) * (b % 2 ? a : 1) : 1; }
const int mod = 1000000007;
ll modpow(ll a, int b) { return b ? modpow(a * a % mod, b / 2) * (b % 2 ? a : 1) % mod : 1; }
template<class T> ostream& operator<<(ostream& os, const vector<T>& v) { rep(i, sz(v)) { if (i) os << " "; os << v[i]; } return os; }
template<class T, class U> ostream& operator<<(ostream& os, const pair<T, U>& p) { os << p.F << " " << p.S; return os; }
template<class T> inline void add(T &a, int b) { a += b; if (a >= mod) a - mod; }

void solve();

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int T;
    // cin >> T;
    T = 1;

    while (T--) {
      solve();
    }
}

// https://atcoder.jp/contests/ddcc2019-qual/submissions/9899069

ll ext_gcd(ll a, ll b, ll &x, ll &y) {
  if (b == 0) {
    x = 1, y = 0;
    return a;
  }
  ll x2, y2;
  ll d = ext_gcd(b, a % b, x2, y2);
  x = y2;
  y = x2 - (a / b) * y2;
  return d;
}

ll mod_inv(ll a, ll m) {
  ll x, y;
  ll d = ext_gcd(a, m, x, y);
  if (d != 1) {
    return -1;
  }
  x %= m;
  if (x < 0) x += m;
  return x;
}

// https://yukicoder.me/submissions/289727

ll garner(const vector<ll> &r, vector<ll> m, ll mod) {
    int n = sz(r);
    m.emplace_back(mod);
    vector<ll> m_prod(n + 1, 1); // coeffs[i]v_i
    vector<ll> x(n + 1);
    rep(i, n) {
        ll t = (r[i] - x[i]) * mod_inv(m_prod[i], m[i]) % m[i];
        if(t < 0) t += m[i];
        rep3(j, i + 1, n + 1) {
            (x[j] += m_prod[j] * t % m[j]) % m[j];
            (m_prod[j] *= m[i]) % m[j];
        }
    }
    return x.back();
}

/* bug
ll garner(const vector<ll> &r, vector<ll> m, ll mod) {
    int n = sz(r);
    m.emplace_back(mod);
    vector<ll> m_prod(n + 1, 1); // coeffs[i]v_i
    vector<ll> x(n + 1);
    x[0] = r[0] % m[0];
    rep3(i, 1, n) {
        rep3(j, i + 1, n + 1) {
            (m_prod[j] *= m[i]) % m[j];
        }
        ll t = (r[i] - x[i]) * mod_inv(m_prod[i], m[i]) % m[i];
        if(t < 0) t += m[i];
        rep3(j, i + 1, n + 1) {
            (x[j] += m_prod[j] * t % m[j]) % m[j];
        }
    }
    return x.back();
}
*/
map<ll, int> prime_factorize(ll n) {
    ll tmp = n;
    map<ll, int> mp;
    for (ll i = 2; i * i <= n; ++i) {
        ll cnt = 0;
        while (tmp % i == 0) {
            tmp /= i;
            cnt++;
        }
        if (cnt) mp[i] = cnt;
    }
    if (tmp != 1) mp[tmp] = 1;
    return mp;
}

void solve() {
  int n;
  cin >> n;
  vector<pair<ll, ll> > g(n);
  rep(i, n) cin >> g[i].F >> g[i].S;

  map<ll, int> mp, mp2;
  vector<map<ll, int> > v(n);
  rep(i, n) v[i] = prime_factorize(g[i].S);
  rep(i, n) {
    for (auto e : v[i]) {
      if (chmax(mp[e.F], e.S)) {
        mp2[e.F] = i;
      }
    }
  }
  // for (auto e : mp) cout << e.F << " " << e.S << " " << mp2[e.F] << endl;

  vector<ll> r(n), m(n);
  rep(i, n) r[i] = g[i].F, m[i] = g[i].S;
  for (auto e : mp) {
    rep(i, n) {
      if (!v[i].count(e.F) || i == mp2[e.F]) continue;

      if (r[i] % e.F != r[mp2[e.F]] % e.F) {
        cout << -1 << endl;
        return;
      }

      ll d = pow(e.F, v[i][e.F]);

      m[i] /= d;
      r[i] %= m[i];
    }
    // cout << endl << e.F << endl;
    // rep(i, n) cout << r[i] << " " << m[i] << endl;
  }
  // rep(i, n) cout << r[i] << " " << m[i] << endl;
  ll x = garner(r, m, mod);
  // cout << x << endl;
  // 無理やり互いに素にした
  // 情報が失われてる
  /* debuged
  rep(i, n) {
    cout << x % g[i].S << " " << g[i].F << endl;
    if (x % g[i].S != g[i].F) {
      cout << -1 << endl;
      return;
    }
  }

  2 4
  mod = 13
  14 % 4 = 2

  14 % 13 = 1
  1 % 4 = 1 != 2
  */

  // r がすべて 0 のとき, 答えが 0 になる
  // このとき, すべての m をかけたの足す
  ll L = 1;
  rep(i, n) {
    if (r[i] != 0) break;

    (L *= m[i]) %= mod;
    if (i == n - 1) {
      cout << L << endl;
      return;
    }
  }

  cout << x << endl;
}

/*
2
1 4
2 8

1 4 to 0 1
間違ってはないが, 情報が失われてる
*/