using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Practice
{
    class Program
    {
        static void Main(string[] args)
        {
            Solve();
        }
        private const long MOD = 1000000007;
        
        static void Solve()
        {
            int n = ReadAndParseInt();
            var t = new int[n];
            var a = new int[n];
            for(int i=0;i<n;++i)
            {
                var o = ReadAndParseIntArr();
                t[i] = o[0];
                a[i] = o[1];
            }

            long curT = t[0];
            long curA = a[0];
            for(int i=1;i<n;++i)
            {
                long ti = t[i];
                long ai = a[i];
                if( ti != ai)
                {
                    long coefT = (curT-1) / ti + 1;
                    long nextT0 = coefT * ti;
                    long nextA0 = coefT * ai;
                    bool valid0 = nextT0 >= curT && nextA0 >= curA;

                    long coefA = (curA-1) / ai + 1;
                    long nextT1 = coefA * ti;
                    long nextA1 = coefA * ai;
                    bool valid1 = nextT1 >= curT && nextA1 >= curA;
                    if( valid0 && valid1)
                    {
                        if( nextT0 + nextA0 <= nextT1 + nextA1)
                        {
                            curT = nextT0;
                            curA = nextA0;
                        }
                        else
                        {
                            curT = nextT1;
                            curA = nextA1;
                        }
                    }
                    else if( valid0)
                    {
                        curT = nextT0;
                        curA = nextA0;
                    }else if( valid1)
                    {
                        curT = nextT1;
                        curA = nextA1;
                    }
                    
                }else {
                    curT = Math.Max(curT, curA );
                    curA = curT;
                }

            }

            Console.WriteLine(curT + curA);
        }
        #region よく使う便利関数
        private static bool isPrime(long x)
        {
            if (x == 2) { return true; }
            if (x < 2 || x % 2 == 0) { return false; }
            long i = 3;
            while (i * i <= x)
            {
                if (x % i == 0) { return false; }
                i = i + 2;
            }
            return true;
        }
        private static long lcm(long x, long y)
        {
            return x / gcd(x, y) * y;
        }
        private static long gcd(long x, long y)
        {
            return y > 0 ? gcd(y, x % y) : x;
        }
        private static long pow(long x, long n)
        {
            if (n == 0) { return 1; }
            long res = pow(x * x % MOD, n / 2);
            if (n % 2 == 1)
            {
                res = res * x % MOD;
            }
            return res;
        }
        private static int ReadAndParseInt()
        {
            return int.Parse(Console.ReadLine());
        }
        private static int[] ReadAndParseIntArr()
        {
            return Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
        }
        private static long ReadAndParseLong()
        {
            return long.Parse(Console.ReadLine());
        }
        private static long[] ReadAndParseLongArr()
        {
            return Array.ConvertAll(Console.ReadLine().Split(' '), long.Parse);
        }
        #endregion
    }
}

Measured memory_bytes: 13140