def search(matrix,value):
sizex = len(matrix[0])-1
sizey = len(matrix)-1
initialx = sizex
initialy = 0
while initialx >= 0 and initialy <= sizey:
if matrix[initialy][initialx] == value:
return initialx,initialy
elif matrix[initialy][initialx] > value:
initialx -= 1
elif matrix[initialy][initialx] <= value:
initialy += 1
else:
return -1,-1
return -1,-1
M = [ [ 1, 5, 7, 9 ],
[ 4, 6, 10, 15 ],
[ 8, 11, 12, 19 ],
[ 14, 16, 18, 21 ] ]
value = 12
print(search(M,value))
value = 17
print(search(M,value))