#include<iostream> #include<cstdio> using namespace std; int main() { int m; double s; cin>>m; s = 0; if (m>10){ s = 6+(10-2)*1.8+(m-10)*2.7; } else{ if(m>2){ s = 6+(m-2)*1.8; } else{ s=6; } } cout<<s; return 0; }