A - Bachgold Problem vj

A - Bachgold Problem

CodeForces - 749A

Bachgold problem is very easy to formulate. Given a positive integer
n represent it as a sum of maximum possible number of prime numbers. One can prove that such representation exists for any integer greater than1.

Recall that integer k is called
prime if it is greater than 1 and has exactly two positive integer divisors —1 and
k.

Input

The only line of the input contains a single integer n (2 ≤ n ≤ 100 000).

Output

The first line of the output contains a single integer
k — maximum possible number of primes in representation.

The second line should contain k primes with their sum equal ton. You can print them in any order. If there are several optimal solution, print any of them.

Example

Input

5

Output

2
2 3

Input

6

Output

3
2 2 2

#include <stdio.h>
#include <stdlib.h>

int main()
{
int a;
int i,j;
int k;
int b,c,d;
scanf("%d",&a);
b = a / 2;
if(a%2==1)
{

printf("%d\n",b);
for(i = 0;i < b-1;i++)
printf("2 ");
printf("3");
}
else
{
printf("%d\n",b);
for(i = 0;i < b - 1;i++)
printf("2 ");
printf("2");
}
return 0;
}