CGPA the Golden Egg!

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int i,n,c;
    double m,a,b,sum,sum1,p;
    cin>>n;
    for(i=1;i<=n;i++)
    {
        sum=0,sum1=0,p=0,c=0;
        cin>>m;
        while(m--)
        {
            cin>>a>>b;
            if(a>=80)
            {
                p=4*b;
            }
            else if(a>=75)
            {
                p=3.75*b;
            }
            else if(a>=70)
            {
                p=3.50*b;
            }
            else if(a>=65)
            {
                p=3.25*b;
            }
            else if(a>=60)
            {
                p=3*b;
            }
            else if(a>=55)
            {
                p=2.75*b;
            }
            else if(a>=50)
            {
                p=2.50*b;
            }
            else if(a>=45)
            {
                p=2.25*b;
            }
            else if(a>=40)
            {
                p=2*b;
            }
            sum=sum+b;
            sum1=sum1+p;
            if(a<40)
            {
                c++;
            }
        }
        if(c>0)
        {
            cout<<"Case "<<i<<": Sorry, you have failed in "<<c<<" courses!"<<endl;
        }
        else
        {
            cout<<fixed<<setprecision(2)<<"Case "<<i<<": "<<sum1/sum<<endl;
        }
    }
}

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