#12871: _C++
eric50216
(NUU EE)
#include<iostream>
using namespace std;
main(){
int N;
while(cin>>N)
{
cout<<50*(N/12)+5*(N%12)<<endl;
}
}
#include<iostream>
using namespace std;
main(){
int N;
while(cin>>N)
{
cout<<50*(N/12)+5*(N%12)<<endl;
}
}