B. CGPA (LU Intra 2020)

/********************
Riz1 Ahmed, CSE, LU.
fb.com/riz1ahmed
Code Start Time: 2020-02-09-17.20
********************/
#include<bits/stdc++.h>
#define Fast ios_base::sync_with_stdio(0),cin.tie(0),cout.tie(0);
#define FOR(i,l,r) for(i=l;i<=r;i++)
#define ll long long int
void Print(ll n) {printf("%lld\n",n);}
const ll Mod=1e9+7,MX=1e7;
using namespace std;
struct R{ double cr,gpa;};

double totcr,totgpa;

bool cmp(R a,R b){
    double acgpa=(totgpa-a.gpa+4)/(totcr);
    double bcgpa=(totgpa-b.gpa+4)/(totcr);

    return (acgpa<bcgpa);
}
int main(){
    string s;
    double n,ex,i,cr,gpa;
    while(cin>>n>>ex){
        vector<R> v;
        totcr=0,totgpa=0;
        for (i=0; i<n; i++){
            cin>>s>>cr>>gpa;
            if (!gpa) continue;
            //printf("%.1f,%1f\n",cr,gpa);
            if (gpa<=2.75) v.push_back({cr,gpa});
            totgpa+=cr*gpa;
            totcr+=cr;
            //printf("Total Creadit=%.1f, Total CGPA=%.1f\n",totcr,totgpa);
        }
        double cgpa=totgpa/totcr;
        int c=0;
        //printf("CGPA=%.1f\n\n",cgpa);
        sort(v.begin(), v.end(),cmp);
        //for (auto it:v) printf("%.1f %.1f\n",v[i].cr,v[i]);
        //printf("%.0lf\n",c);
        while (v.size() && cgpa<ex){
            c++;
            cr=v.back().cr, gpa=v.back().gpa, v.pop_back();
            totgpa-=cr*gpa, totgpa+=cr*4.0;
            cgpa=totgpa/totcr;
        }
        if(cgpa<ex) puts("Impossible");
        else printf("%d\n",c);
    }

    return 0;
}