Problems

# 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