#!/usr/bin/Rscript
number_of_grid_routes <- function(n)
{
        if(n<1) return(FALSE)
        if(n==1) return(2)
        return(number_of_grid_routes(n-1) * (2*n * (2*n-1)) / (n * n));
}

for(i in commandArgs(TRUE)) print(number_of_grid_routes(as.numeric(i)))