curves = [[1,a+1,a,a,0],
[1,-a-1,a,0,0],
[a,a-1,a,-1,-a+1],[0,-a,a,0,0],[0,a-1,a+1,0,-a],
[1,1,1,0,0],[0,a,1,1,0],[1,-a+1,1,-a,0],[1,a,1,a-1,0],
[0,a-1,0,-a,0],[a,a+1,a,a,0], [a+1,a-1,1,0,0] , [a,-a+1,1,-1,0],
[a+1,0,1,-a-1,0],[1,0,a+1,-2*a-1,0] , [1,0,a,a-2,-a+1],
[a,a+1,0,a+1,0], [a+1,a-1,a,0,0] ,[0,1,0,-1,0],[1,-1,a,-2*a,a] ,
[a+1,-1,1,-a-1,0],[a,-a,1,-1,0] ,[a,a+1,a,2*a,a],
[a+1,a-1,1,-a+1,-1],[a+1,0,0,1,0],[a,-a+1,0,1,0],
[1,0,1,-1,-2], [a,a-1,a+1,-a,-a], [1,-1,a,-a,0], [1,-a,a,a+2,-a] , [1,a-1,a+1,-2*a+3,-1],
[a+1,a-1,a+1,-1,-a+1],
[a,a+1,1,1,0]]