eolymp
Problems

01110001, That Is the Question

01110001, That Is the Question

As you know, the number in binary is written using the digits 0 and 1. You must convert number from binary to decimal.

Input

One nonnegative integer in binary notation. Contains no more than 15 digits. The notation can start from zeros.

Output

Print the number in decimal notation.

Time limit 1 second
Memory limit 122.17 MiB
Input example #1
101
Output example #1
5
Input example #2
01
Output example #2
1
Input example #3
00110011
Output example #3
51
Input example #4
1111
Output example #4
15
Source The 2012 All-Ukrainian Collegiate Programming Contest Round I Training Contest 19 April 2012