Find Last Digit (keteki)

This is a sequence 1, N+1, 2, N+2, 3, N+3, 4, N+4, 5, ..... N, 2*N Input is two consecutive numbers in the sequence, first number in odd position and second number in even position, print the last digit in the sequence. The two consecutive numbers would be on a newline separated by a space. Note: Long value. ###Constraints - $1 \leq 2*N \leq 1E12$ (10 to the power 12) ###Subtasks 5 subtask