Every walk step is made, direction and size of which are either x or y and +1 and -1, respectively.
Three arguments: pbc/nopbc L steps
Either pbc (periodic boundary conditions) or nopbc can be chosen.
Boundaries: xlo = -2/L, xhi = 2/L, ylo = -2/L, yhi = 2/L
Number of steps to be made: steps
make
./randomwalk pbc 10 1000