题解

#include<iostream>
#include<algorithm>
using namespace std;
struct pineapple{
    int k,p;
}a[1000010];
bool cmp(pineapple a,pineapple b){
    return a.p<b.p;
}
int main(){
    int n,r;
    long long sum=0;
    cin>>n>>r;
    for(int i=0;i<n;i++){
        cin>>a[i].k>>a[i].p;
    }
    sort(a,a+n,cmp);
    for(int i=0;i<r;i++){
        if(a[i].p==0){
            continue;
        }else{
            long long x=a[i].k*(r/a[i].p);
            sum=max(x,sum);
        }
    }
    cout<<sum;
    return 0;
}