Score : 300 points
Snuke has decided to play with a six-sided die. Each of its six sides shows an integer 1 through 6, and two numbers on opposite sides always add up to 7.
Snuke will first put the die on the table with an arbitrary side facing upward, then repeatedly perform the following operation:
For example, let us consider the situation where the side showing 1 faces upward, the near side shows 5 and the right side shows 4, as illustrated in the figure. If the die is rotated toward the right as shown in the figure, the side showing 3 will face upward. Besides, the side showing 4 will face upward if the die is rotated toward the left, the side showing 2 will face upward if the die is rotated toward the front, and the side showing 5 will face upward if the die is rotated toward the back.
Find the minimum number of operation Snuke needs to perform in order to score at least x points in total.
The input is given from Standard Input in the following format:
x
Print the answer.
7
2
149696127901
27217477801