def dl_prod(i, j):
"""
Return the product of 4 consecutive diagonal entries in the grid starting at
(i, j) and moving down-left. 'i' indexes rows and 'j' indexes colums, from
the top-left of the grid.
"""
if j < 3 or i > 16:
return -1
else:
return product(GRID[i+k][j-k] for k in range(4))
def h_prod(i, j):
"""
Return the product of 4 consecutive horizontal entries in the grid starting
at (i, j) and moving right. 'i' indexes rows and 'j' indexes colums, from
the top-left of the grid.
"""
if j > 16:
return -1
else:
return product(GRID[i][j+k] for k in range(4))
def num_divisors(n):
p_factors = Counter(prime_factors_large_n(n))
p_factors.update(p_factors.keys()) # Add '1' to every Counter entry
return product(p_factors.values())
def solve():
return sum(int(digit) for digit in str(product(range(1, 101))))
