#include <iostream> using namespace std; int z[7]={3,4,6,9,12,14,15}; int main() { int n; while(scanf("%d",&n)!=EOF) { if(n==1)printf("3\n"); else if(n==2)printf("5\n"); else if(n==3)printf("6\n"); else if(n>=4) { int sum=15,m=(n-3)/7,mol=(n-3)%7,ans; if(mol>=1) ans=15*m+z[mol-1]+6; else if(mol==0) ans=15*m+6; printf("%d\n",ans); } } return 0; }