/*MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMWO:,'..'xXWWMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMO. .:kOo.,kNMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMO. .lNWWo..lXMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
MNOxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxMMMMWKxoloxKWNc  .:xxd;  ,dxxxkXMXkxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxMM
MKc''''''''''''''''.  ..'''''.   .''''.  .''MMMWx..,:. .xXo''.  .''.  ..'';kMk;'''''.  .'.''.  .''''''.  ..''.   .''MM
MWNXNNNNNNNNNNNNNNNO' ;KNNNNNKo. cKNNNd. lXNMMMK; ,0Wx. :NWXXl .dNNO' ;KNNNWMWNNNNNXc .kNNNNx. cXNNNNNO' ;KNN0; 'ONNMM
MMMMMMMMMMMMMMMMMWM0' :NMMMMWMX: .OMWWx. oWMMMMWx. ';. .dNMWWo .xMM0' :NWWMMMMMMMMWWl .OMMMWk. lWWMMWM0' ;XMMX: ,KMMMM
MMMMMMWMWkccccccccc;. :NMWNNNKd. :XMMWx. oWMMMWKo. .',. .,ldx; .dMM0' :NMMMMMMMNNWMWl .OMMMWk. lWMMMMM0' ;XMMX: ,0MMMM
MMWXKNWMWxcc,. .;cc;. :XMk,''..'lKWMMWx. oWMNx:. .lONNKxl.     .xMM0' :NMMMMMM0:,oKO' ,KMMMMk. lWWNkoc,. .;::;. ,KMMMM
MMXc.lXMMWWWNd..xWM0' :NM0;  ;kXWMMMWNl  oWMK:.;xXWWMWXx:. ,c' .dMM0' :NMMMMMMKc. ...;kWMMMMk. lWWc .:;. .clc:. ,KMMMM
MWWx. lXMWMMMK, lWM0' :NMMNx'.,ldxxoc'   oWMWNKNWWWN0o' .:kNWo .dMM0' :NMMMMMMMNO;  ,OWWWMMMk. lWM' lXx. lNMMX: ,KMMMM
MMMWk'.,xKNX0c..kWM0' :NMMMMNkl;,'',:l:  oWMMMMMWMWO' 'l0WMWWo .xMM0' :NMMMMMMMMMNd. .oXWMMMk. lWMd.....;0WMMX: ,KMMMM
MMMMWKo'...'..:kWMM0' :NMMMMMMMWWNNWWWx. oWMMMMMMMMWOxXWMWMWWo .xMM0' :NMMMMMMMMMMMKl. ,kNMMk. lWMWKkxx0NMWMMX: ,KMMMM
MMMMMMMN0kxk0XNWMMWKl;xNMMMMMMMMMMMMWM0c;kWMMMMMMMMMMMWWMMMMWk;:OMMXl,dNMMMMMMMMMMMMWO; .dNM0c;kWWMMMMMMMMMMMNd,oXMMMM
MMMMMMMMWWMWMMMMMMMMMWWMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMWWMMWWMMWMMMMMMMMMMMMMMNkxKWMMWWMMMMMMMMMMMMMMWMMWMMMMM
MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM*/

//             Author: Udit "luctivud" Gupta @ (https://www.linkedin.com/in/udit-gupta-1b7863135/)                  //


#include <bits/stdc++.h>
#pragma GCC optimize "trapv"

using namespace std;

// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;

// template <typename T> using FSET = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int lld;
typedef unsigned long long int llu;

#define         TESTCASES()    cin >> (T3X0); T353 = T3X0; while(T3X0--)
#define          input(V3C)    for(auto &V3C_I7 : (V3C)) cin >> (V3C_I7)
#define   mems(A77AY, V4LU)    memset((A77AY), (V4LU), sizeof((A77AY)))
#define    CH3K(I7, E4, S7)    (((S7)>0) ? (I7)<(E4) : (I7)>(E4))
#define   for4(I7,S4,E4,S7)    for(auto I7=(S4); CH3K(I7,E4,S7); (I7)+=(S7))
#define        EACH(I7, A7)    for (auto& I7: A7)
#define              len(v)    ((int)((v).size()))
#define              all(x)    (x).begin(), (x).end()
#define             rall(x)    (x).rbegin(), (x).rend()
#define                  pb    push_back
#define             deb1(x)    cout << #x << "=" << (x) << "\n";
#define             deb2(x)    cout << #x << "=" << (x) << " ";



#define error(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }

void err(istream_iterator<string> it) {}
template<typename T, typename... Args>
void err(istream_iterator<string> it, T a, Args... args) {
	cout << *it << " = " << a << endl;
	err(++it, args...);
}

void read() { return; }
void print() { return; }
void println() { return; }
template<class T> T read(T& x)   { cin >> x; return x; }
template<class T> void print(T a)   { cout << a; }
template<class T> void println(T a) { cout << a << "\n"; }

template<class T> void read(vector<T> &arr)   { EACH(i, arr) cin >> (i); }
template<class T> void print(vector<T> arr)   { EACH(i, arr) {cout << i << " ";} }
template<class T> void println(vector<T> arr) { EACH(i, arr) {cout << i << " ";} cout << "\n"; }

template<class T> void read(vector<vector<T>> &arr)   { EACH(i, arr) read(i); }
template<class T> void print(vector<vector<T>> arr)   { EACH(i, arr) println(i); }
template<class T> void println(vector<vector<T>> arr) { EACH(i, arr) println(i); }

template<typename T, typename... Args> void read(vector<T> &arr, Args &... args)   { read(arr); read(args...);}
template<typename T, typename... Args> void read(vector<vector<T>> &arr, Args &... args)   { read(arr); read(args...);}
template<typename T, typename... Args> void read(T &a, Args &... args) { cin >> (a); read(args...); }
template<typename T, typename... Args> void print(vector<T> &arr, Args &... args)   { print(arr); print(args...);}
template<typename T, typename... Args> void print(T a, Args... args) { cout << a << " "; print(args...); };
template<typename T, typename... Args> void println(vector<T> &arr, Args &... args)   { print(arr); println(args...);}
template<typename T, typename... Args> void println(T a, Args... args) { cout << a << " "; println(args...); };


const int d4i[4] = { -1, 0, 1, 0}, d4j[4] = {0, 1, 0, -1};
const int d8i[8] = { -1, -1, 0, 1, 1, 1, 0, -1}, d8j[8] = {0, 1, 1, 1, 0, -1, -1, -1};

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////



const lld inf = INT_MAX;

void solveEachTest(lld _TestCase = 1) {
	// cout << "Case#" << _TestCase << ": ";
	lld n; read(n);
	lld a = 1, b = 1;

	for4(xx, 0, n , 1) {
		lld x, y;
		read(x, y);
		lld j = 1ll;
		lld l = 1ll, r = max(a/x, b/y)+1;
		while (l <= r) {
			lld mid = l + (r- l)/2;
			// println(mid, l, r);
			if (mid * x >= a and mid * y >= b) {
				j = mid;
				r = mid - 1ll;
			} else {
				l = mid + 1ll;
			}
		}

		a = x * j, b = y * j;
		// error(a, b, j);
	}

	println(a + b);

	// cout << "\n";
	return;
}


signed main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.precision(10);

	lld T3X0 = 0, T353 = 1;

	// TESTCASES()
	solveEachTest(T353 - T3X0);
	return 0;
}
// Random Thought :  null

Measured memory_bytes: 3596