#include<iostream>
#include<algorithm>
#include<map>
#include<cstdio>
#define ll long long
#define lson (rt<< 1)
#define rson (rt<< 1 | 1)
#define gmid ((l+r)>> 1 )
using namespace std;

const int maxn=20000050;


ll n,m,x[maxn],y[maxn];

struct node
{
    double s;
    int k;
}a[maxn];

bool cmp(node x,node y)
{
    return x.s<y.s;
}
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        cin>>n>>m;
        for(int i=1;i<=n;++i)
        {
            cin>>x[i]>>y[i];
            a[i].s=((y[i]*1.0)/x[i]);
            a[i].k=i;
        }
        int j=m;
        sort(a+1,a+n+1,cmp);
        ll ans=maxn,sum=0;  
        for(int i=1;i<=n;++i)
          {
                j=m;
                int z=a[i].k;
                while(j>=x[z])
                {
                      j-=x[z];
                      sum+=y[z];
                }
                if(j>0)
                {
                      ans=min(sum+y[z],ans);
                }
                else ans=min(sum,ans);
          }
        cout<<ans<<endl;  
    }
}