Ravinder can cut a tree in 6 days, Sudhir can cut the same tree in 12 days and Sunder can cut it in 18 days. Ram is thrice as efficient as Sunder. If Ravinder worked on the same tree for 1 days, Sudhir worked for 2 days and Sunder worked for 3 days. Find the number of days Ram will take to cut the remaining tree alone.