URI 1985 problem solve in c++

problem details: https://www.urionlinejudge.com.br/judge/en/problems/view/1985

Solution in C++:

#include <iostream>
#include <iomanip>

using namespace std;

int main()
{
    int a;double sum=0.0;
    cin>>a;
    for(int b=1;b<=a;b++){
    int c,d;
    cin>>c>>d;
        if(c==1001){
            sum=sum+(d*1.50);
        }
        else if(c==1002){
            sum=sum+(d*2.50);
        }
         else if(c==1003){
            sum=sum+(d*3.50);
        }
         else if(c==1004){
            sum=sum+(d*4.50);
        }
         else if(c==1005){
            sum=sum+(d*5.50);
        }
    }
    cout << fixed<<setprecision(2)<<sum << endl;
    return 0;
}