#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cstring>

#include<cmath>

#include<algorithm>

#define il inline

#define rg register

#define ll long long

#define N 10001

#define inf 1000000010

using namespace std;

int n,a,b;

struct T{

    int le,ri;

}h[N];

ll now[N],ans[N],zs[N];

int len1,alen,flag;

il void re(rg int &x);

int cmp(const T &x,const T &y);

void solve(rg int k);

void add(rg int k);

int main()

{

    re(n),re(a),re(b);

    for(rg int i=;i<=n;++i)

        re(h[i].le),re(h[i].ri);

    sort(h+,h+n+,cmp);

    while(a)

        now[++len1]=(a%),a/=;

    for(rg int i=;i<=n;++i)

        solve(i),add(i);

    for(rg int i=len1;i>=;--i){

        if((!flag)&&(!ans[i]))continue;

        cout<<ans[i];

        flag=;

    }

    return ;

}

il void re(rg int &x){

    rg int res=,w=;char c=getchar();

    while((c<''||c>'')&&c!='-')c=getchar();

    if(c=='-')w=-,c=getchar();

    while(c>=''&&c<='')res=(res<<)+(res<<)+c-'',c=getchar();

    x=w*res;

}

int cmp(const T &x,const T &y){

    return (x.le*x.ri)<(y.le*y.ri);

}

void solve(rg int k){

    memset(zs,,sizeof(zs));

    rg int c=h[k].ri,p=;

    for(rg int i=len1;i>=;--i){

        p=p*+now[i];

        zs[i]=p/c,p%=c;

    }

    for(rg int i=len1;i>=;--i){

        if(ans[i]==zs[i])continue;

        if(ans[i]>zs[i])break;

        memcpy(ans,zs,sizeof(zs));

        break;

    }

}//除以自己右手上的值统计

void add(rg int k){

    rg int c=h[k].le;

    for(rg int i=;i<=len1;++i)

        now[i]*=c;

    for(rg int i=;i<=len1;++i){

        if(now[i]>=){

            rg int w=i;

            while(now[w]>=){

                now[w+]+=now[w]/,now[w]%=,w++;

                if(w>len1)len1=w;

            }

        }

    }

    while(now[len1+]>=)

        now[len1+]=(now[len1]/),now[len1]%=,len1++;

}