CZ-SK-MO 1994 Problem 3

A convex $1994$ -gon $M$ is given in the plane. A closed polygonal line consists of $997$ of its diagonals. Every vertex is adjacent to exactly one diagonal. Each diagonal divides $M$ into two sides, and the smaller of the numbers of edges on the two sides of $M$ is defined to be the length of the diagonal. Is it posible to have (a) $991$ diagonals of length $3$ and $6$ of length $2$ ? (b) $985$ diagonals of length $6, 4$ of length $8$ , and $8$ of length $3$ ?