#include<bits/stdc++.h>
#define int long long
#define il inline
#define re register 
using namespace std;
const int k = 10000;
struct node {
	int a, b;
	bool operator < (const node x) const {
		return a * b < x.a * x.b;
	}
};
node a[1005], x;
int n, sum[1000005], top, tmp[1000005], ans[1000005], idx, tot;
bool pd () {
    if (tot != idx) return top > idx;
    for (int i = idx; i >= 1; -- i) {
    	if (tmp[i] != ans[i]) {
    		return tmp[i] > ans[i]; 
		}
	}
	return 0;
}
void mul (int x) {
	for (int i = 1; i <= top; ++ i) {
		sum[i] *= x;
		sum[i + 1] += sum[i] / k;
		sum[i] %= k;
	}
	while (sum[top + 1]) ++ top, sum[top + 2] += sum[top + 1] / k, sum[top + 1] %= k;
	return;
}
void chu (int x) {
	int cnt = 0;
	for (int i = tot; i >= 1; -- i) {
		cnt = cnt * k + sum[i];
		tmp[i] = cnt / x;
		cnt %= x;
	}
	while (!tmp[tot]) -- tot;
	return;
}
signed main(){
	cin >> n;
	cin >> x.a >> x.b;
	for (int i = 1; i <= n; ++ i) cin >> a[i].a >> a[i].b;
	sort(a + 1, a + n + 1);
	int p = x.a;
	do {
		sum[++ top] = p % k;
		p /= k;
	} while (p);
	for (int i = 1; i <= n; ++ i) {	
		for (int j = 1; j <= top; ++ j) tmp[j] = 0;
		tot = top;
	    chu(a[i].b);		
		if (pd()) {
	    	for (int j = 1; j <= tot; ++ j) ans[j] = tmp[j];
	    	idx = tot;
		}	
		mul(a[i].a);
	}
	for (int i = idx; i >= 1; -- i) cout << ans[i];
	return 0;
}