#include<bits/stdc++.h> using namespace std; int read() { char s; int k=0,base=1; while((s=getchar())!='-'&&s!=EOF&&!(s>='0'&&s<='9')); if(sEOF)exit(0); if(s'-')base=-1,s=getchar(); while(s>='0'&&s<='9') { k=k10+(s-'0'); s=getchar(); } return kbase; } void write(int x) { if(x<0) { putchar('-'); write(-x); } else { if(x/10)write(x/10); putchar(x%10+'0'); } } int n,A,B; struct node { int x,y; } a[1010]; bool cmp(node aa,node bb) { if (aa.xaa.y==bb.xbb.y) return aa.y<bb.y; return (aa.xaa.y)<(bb.xbb.y); } int sum[1010]; int ans[1010],ls; int p[1010],lp; int m;//sum长度 int P; bool Max()//比大小,ans>p: true { int i=1; while (p[i]==0&&i<=lp) i++;//去掉前面的0 int j=1; while (ans[j]==0&&j<=ls) j++; if (lp-i+1>ls-j+1) return false;//p的位数>ans的位数 if (lp-i+1<ls-j+1) return true; while (i<=lp&&j<=ls)//一位一位的比较 { if (p[i]<ans[j]) return true; if (p[i]>ans[j]) return false; i++; j++; } return false; } void cheng(int d) { for (int i=1;i<=m;i++) sum[i]=a[d].x;//高精度乘法 for (int i=1;i<=m;i++)//进位 { sum[i+1]+=sum[i]/10000; sum[i]%=10000; } if (sum[m+1]!=0) m++; } void div(int d) { memset(ans,0,sizeof(ans)); ls=1; while (m>0&&sum[m]==0) m--;//去掉前导0 P=0; int flag=0; for (int i=m;i>=1;i--)//高精度除法(模拟竖式) { P=P10000+sum[i]; ans[++ls]=P/a[d].y; if (ans[ls]==0&&!flag) ls--; else flag=1; P%=a[d].y; } } int main() { n=read(); A=read(); B=read(); for (int i=1;i<=n;i++) a[i].x=read(),a[i].y=read(); sort(a+1,a+n+1,cmp); m=1; sum[1]=A; for (int i=1;i<=n;i++) { div(i); if (Max()) { lp=ls; memcpy(p,ans,sizeof(ans)); } cheng(i); } int i=0; while (i<=lp&&p[i]==0) i++; printf("%d",p[i]);i++; for (;i<=lp;i++)//输出 { if (0<=p[i]&&p[i]<=9) printf("000%d",p[i]);else if (10<=p[i]&&p[i]<=99) printf("00%d",p[i]);else if (100<=p[i]&&p[i]<=999) printf("0%d",p[i]);else printf("%d",p[i]); } return 0; }