Powers of two#4208
It is well known that for any non-negative integer , the number 2^n has a very simple representation in binary: a single one in the highest bit followed by zeros. In the decimal system, these numbers are not so uniform; however, among them, there are some that begin with the digit one.
Print the number of such numbers in the given range.
Two integers n_1 and n_2 (0 \leq n_1 < n_2 \leq 10^9), separated by a space.
Print the number of powers of two in the interval [2^{n_1};\, 2^{n_2}] whose decimal representation begins with the digit .
Example 1