Nails and Rubber Bands. That is the suggestive name of a game played by a group of children (all of them offspring of geometry teachers). The children fix a number of nails on a plank of wood, at random positions. Then they choose one of the nails to be the Origin and prepare $B$ rubber bands. The challenge is to use the $B$ rubber bands to wrap the nails so that:
An instance of the game is shown in Figure 1.

Figure 1: A game with 19 nails and 2 rubber bands
Your program must solve several instances of the game. Each game description starts with a line containing two integers $B$ and $N$, giving respectively the number of rubber bands and the number of nails, with $2 \le B \le 50$ and $2B+1 \le N \le 101$. The following $N$ lines describe the positions of the nails; each line contains two integers $X$ and $Y$ ($-10000 \le X, Y \le 10000$). The Origin is the first nail in the input. The end of input is indicated by $B = N = 0$.
In every game in the input:
For each game, output a single line with the smallest total area covered by the wrappings. Print the area as a real number with two decimal places, rounding the last digit. The input contains no test cases where rounding differences are significant.