def find_previous_digit(number: int, target: int) -> int:
"""
Finds the digit that comes before the target digit when scanning from right to left.
Args:
number (int): The number to search within.
target (int): The digit to find.
Returns:
int: The digit that comes before the target, or -1 if not found or no previous digit.
"""
while number > 0:
current = number % 10
number //= 10
if current == target:
return number % 10 if number > 0 else -1
return -1
number = 8902741
target = 7
result = find_previous_digit(number, target)
if result != -1:
print(f"The digit before {target} in {number} is {result}.")
else:
print(f"The digit {target} is not found or has no previous digit in {number}.")
'''
run:
The digit before 7 in 8902741 is 2.
'''
