#include <iostream>
#include <string>
#include <vector>
#include <numeric>
#include <queue>
#include <unordered_map>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <sstream>
#include <stack>
#include <map>
#include <set>
#include <ios>
#include <cctype>
#include <cstdio>
#include <functional>
#include <cassert>

#define REP(i,a) for(int i = 0;i < (a);++i)
#define FOR(i,a,b) for(int i = (a);i < (b); ++i)
#define FORR(i,a,b) for(int i = (a) - 1;i >=(b);--i)
#define ALL(obj) (obj).begin(),(obj).end()
#define SIZE(obj) (int)(obj).sizeT()
#define YESNO(cond,yes,no){cout <<((cond)?(yes):(no))<<endl; }
#define SORT(list) sort(ALL((list)));
#define RSORT(list) sort((list).rbegin(),(list).rend())
#define ASSERT(cond,mes) assert(cond && mes)

using namespace std;
using ll = long long;

constexpr int MOD = 1'000'000'007;
constexpr int INF = 1'050'000'000;

template<typename T>
T round_up(const T& a, const T& b) {
    return (a + (b - 1)) / b;
}

template <typename T1, typename T2>
istream& operator>>(istream& is, pair<T1, T2>& p) {
    is >> p.first >> p.second;
    return is;
}

template <typename T1, typename T2>
ostream& operator<<(ostream& os, pair<T1, T2>& p) {
    os << p.first << p.second;
    return os;
}

template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
    REP(i, (int)v.size())is >> v[i];
    return is;
}

template <typename T>
ostream& operator<<(ostream& os, vector<T>& v) {
    REP(i, (int)v.size())os << v[i] << endl;
    return os;
}

template <typename T>
T clamp(T& n, T a, T b) {
    if (n < a)n = a;
    if (n > b)n = b;
    return n;
}

template <typename T>
static T GCD(T u, T v) {
    T r;
    while (v != 0) {
        r = u % v;
        u = v;
        v = r;
    }
    return u;
}

template <typename T>
static T LCM(T u, T v) {
    return u / GCD(u, v) * v;
}

bool isAllVisit(const vector<bool>& visit) {
    for (auto&& v : visit) {
        if (!v)return false;
    }
    return true;
}

std::vector<int> enum_div(int n) {
    std::vector<int> ret;
    for (int i = 1; i*i <= n; ++i) {
        if (n%i == 0) {
            ret.push_back(i);
            if (i != 1 && i*i != n) {
                ret.push_back(n / i);
            }
        }
    }
    return ret;
}


int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);

    int N;
    cin >> N;
    vector<pair<ll, ll>> TA(N);
    cin >> TA;

    vector<pair<ll, ll>> dp(N + 1);
    dp[0] = { 1,1 };


    auto solve = [&](int n) {
        if (TA[n].first >= dp[n].first &&TA[n].second >= dp[n].second) {
            return TA[n];
        }
        if (TA[n].first >= dp[n].first) {
            ll mul = round_up(dp[n].second, TA[n].second);
            pair<ll, ll> res = TA[n];
            res.first *= mul;
            res.second *= mul;
            return res;
        }
        else if (TA[n].second >= dp[n].second) {
            ll mul = round_up(dp[n].first, TA[n].first);
            pair<ll, ll> res = TA[n];
            res.first *= mul;
            res.second *= mul;
            return res;
        }
        ll mulT = round_up(dp[n].first, TA[n].first);
        ll mulA = round_up(dp[n].second, TA[n].second);

        pair<ll, ll> res1 = TA[n], res2 = TA[n];
        res1.first *= mulT;
        res1.second *= mulT;
        res2.first *= mulA;
        res2.second *= mulA;

        if (res1.first + res1.second > res2.first + res2.second)return res1;
        else return res2;
    };

    REP(i, N) {
        dp[i + 1] = solve(i);
    }

    cout << dp[N].first + dp[N].second << endl;

    return 0;
}

Measured memory_bytes: 256