Given positive integer \textbf{N} (\textbf{8} ≤ \textbf{N} ≤ \textbf{1000000}), which defines any integer amount of money ≤ \textbf{1000000}. It is known that the integer sum of money greater than or equal to \textbf{7} monetary units, can be requested only bills in denominations of \textbf{2} and \textbf{5} monetary units. Determine how many denominations of \textbf{2} and \textbf{5} units of money can give the amount of \textbf{N} units of money to their total number was minimal. \InputFile Single number - the sum given. \OutputFile Single number - the required minimum number of cuts.