#include<iostream>

 #include<cstdio>

 #include<cstring>

 #define re register

 using namespace std;

 int min(int a,int b){return a<b?a:b;}

 #define P 5000

 int n,m,f[],a,b,ans;

 int main(){

     memset(f,,sizeof(f));ans=f[];f[]=;

     scanf("%d%d",&n,&m);

     for(re int i=;i<=n;++i){

         scanf("%d%d",&a,&b);

         for(re int j=a;j<=m+P;++j)//处理到m+maxP

             f[j]=min(f[j],f[j-a]+b);

     }

     for(re int j=m+P;j>=m;--j) ans=min(ans,f[j]);//在超出的范围中找最小值

     printf("%d",ans);

     return ;

 }