#include <fstream>

using namespace std;
ifstream cin("energii.in");
ofstream cout("energii.out");
int i,n,j,s,w,mi,gmax,g[101],b[1001],v[1001];
int main()
{
    cin>>n;
    cin>>w;
    for(i=1;i<=n;++i)
        {
            cin>>g[i];
            s=s+g[i];

            cin>>v[i];
        }

    b[0]=1;
    mi=9999999;
    for(i=1;i<=n;++i)
        {for(j=s-g[i];j>=1;--j)
            if((b[j]!=0&&b[j+g[i]]==0)||(b[j+g[i]]<b[j]+v[i]))
        b[j+g[i]]=b[j]+v[i];
    if(v[i]>b[g[i]])
        b[g[i]]=v[i];}
    for(i=w;i<=s;++i)
        if(b[i]<mi)
    {
        mi=b[i];
    }
    cout<<mi<<'\n';
    return 0;
}