Snake Ladder Problem!

Rishabh takes out his Snakes and Ladders Game, stares the board and wonders: "If I can always roll the die to whatever number I want, what would be the least number of rolls to reach the destination?"

RULES:

• The game is played with cubic dice of 6 faces numbered from 1 to 6.
• Starting from 1 , land on square 100 with the exact roll of the die. If moving the number rolled would place the player beyond square 100, no move is made.
• If a player lands at the base of a ladder, the player must climb the ladder. Ladders go up only.
• If a player lands at the mouth of a snake, the player must go down the snake and come out through the tail. Snakes go down only.

BOARD DESCRIPTION:

• The board is always 10 x 10 with squares numbered from 1 to 100.
• The board contains N ladders given in a form of 2D matrix A of size N * 2 where (A[i][0], A[i][1]) denotes a ladder that has its base on square A[i][0] and end at square A[i][1].
• The board contains M snakes given in a form of 2D matrix B of size M * 2 where (B[i][0], B[i][1]) denotes a snake that has its mouth on square B[i][0] and tail at square B[i][1].

1 <= N, M <= 15

1 <= A[i][0], A[i][1], B[i][0], B[i][1] <= 100

A[i][0] < A[i][1] and B[i][0] > B[i][1]

Neither square 1 nor square 100 will be the starting point of a ladder or snake.

A square will have at most one endpoint from either a snake or a ladder.

First argument is a 2D matrix A of size N * 2 where (A[i][0], A[i][1]) denotes a ladder that has its base on square A[i][0] and end at square A[i][1].

Second argument is a 2D matrix B of size M * 2 where (B[i][0], B[i][1]) denotes a snake that has its mouth on square B[i][0] and tail at square B[i][1].

Return the least number of rolls to move from start to finish on a separate line. If there is no solution, return -1.

Input 1:

 A = [  [32, 62]
        [42, 68]
        [12, 98]
     ]
 B = [  [95, 13]
        [97, 25]
        [93, 37]
        [79, 27]
        [75, 19]
        [49, 47]
        [67, 17]

Input 2:

 A = [  [8, 52]
        [6, 80]
        [26, 42]
        [2, 72]
     ]
 B = [  [51, 19]
        [39, 11]
        [37, 29]
        [81, 3]
        [59, 5]
        [79, 23]
        [53, 7]
        [43, 33]
        [77, 21] 

Output 1:

 3

Output 2:

 5

Explanation 1:

 The player can roll a 5 and a 6 to land at square 12. There is a ladder to square 98. A roll of 2 ends the traverse in 3 rolls.