how to fix this def calculate_increment(direction: str) -> int: """returns the difference between the string indices of two adjacent squares on a line that goes in the direction specified by the first parameter. >>>calculate_increment(DOWN) 5 >>>calculate_increment(DOWN_RIGHT) 6""" if direction= ACROSS: return 1 elif direction= DOWN_RIGHT: return 6 elif direction= DOWN: return 5 elif direction= DOWN_LEFT: return 4