If number formed by last four digits is divisible by 16.
last = ( int ) ( st [ n - 1 ] ) NEW_LINE second_last = ( int ) ( st [ n - 2 ] ) NEW_LINE third_last = ( int ) ( st [ n - 3 ] ) NEW_LINE fourth_last = ( int ) ( st [ n - 4 ] ) NEW_LINE return ( ( fourth_last * 1000 + third_last * 100 + second_last * 10 + last ) % 16 == 0 ) NEW_LINE