PROGRAMMING:integer partition
Jack Cheng learned that any number can be represented by binary numbers. He can't help but want to play a game. Since it can be represented by binary numbers, it can be written as adding several binary numbers, for example: 7 = 1 + 2 + 47 = 1 + 2 + 2 + 27 = 1 + 1 + 1 + 47 = 1 + 1 + 2 + 2, 7 = 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 2, 7 = 1 + 1 + 1 + 1 + 1 + 1 + 1 + 2, 7 = 1 + 1 + 1 + 1 + 1 + 1 + 1, there are six different splitting methods. Another example: 4 can be divided into 4 = 4, 4 = 1 + 1+
1 + 1，4 = 2 + 2，4=1+1+2。 Use f (n) to represent the number of different splits of N, for example, f (7) = 6. Write a program to read in n (no more than 1000000) and output f (n)% 1000000000. Now he wants you to play the game with him.
###Input format:
Please write the input format here. For example: input 2 integers a and B with absolute value no more than 1000 in one line.
###Output format:
Enter n in the first line to indicate the input, and then enter an N in each line (1 < = n < = 1000000). All the output takes only one line (no extra space at the end of the line).
###Input example:
```in
one
seven
```
###Output example:
```out
six
```
answer：If there is no answer, please comment
1 + 1，4 = 2 + 2，4=1+1+2。 Use f (n) to represent the number of different splits of N, for example, f (7) = 6. Write a program to read in n (no more than 1000000) and output f (n)% 1000000000. Now he wants you to play the game with him.
###Input format:
Please write the input format here. For example: input 2 integers a and B with absolute value no more than 1000 in one line.
###Output format:
Enter n in the first line to indicate the input, and then enter an N in each line (1 < = n < = 1000000). All the output takes only one line (no extra space at the end of the line).
###Input example:
```in
one
seven
```
###Output example:
```out
six
```
answer：If there is no answer, please comment