# you can write to stdout for debugging purposes, e.g.

# print("this is a debug message")

def solution(A):

# write your code in Python 3.6

n = len(A)

maxi = 0

i = 0

jump = 0

visit = [0 for i in range(n)]

while maxi < n:

maxi = A[i] + i

if maxi < n:

visit[maxi] += 1

if visit[maxi] > 5:

return -1

i = maxi

jump += 1

return jump

"""

pawn = A[0]

i = 0

dist = pawn + i

"""

"""

jump = 0

sumi = A[0]

while sumi < n:

i = sumi

sumi = i + A[i]

i += 1

jump += 1

return jump

"""

"""

while dist < n:

i = dist

jump += 1

dist = A[i] + i

return jump+1

"""