codeforces 472A. Design Tutorial: Learn from Math

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

One way to create a task is to learn from math. You can generate some random math statement or modify some theorems to get something new and build a new task from that.

For example, there is a statement called the "Goldbach's conjecture". It says: "each even number no less than four can be expressed as the sum of two primes". Let's modify it. How about a statement like that: "each integer no less than 12 can be expressed as the sum of two composite numbers." Not like the Goldbach's conjecture, I can prove this theorem.

You are given an integer n no less than 12, express it as a sum of two composite numbers.

Input

The only line contains an integer n (12 ≤ n ≤ 106).

Output

Output two composite integers x and y (1 < x, y < n) such that x + y = n. If there are multiple solutions, you can output any of them.

Sample test(s)

input

12

output

4 8

input

15

output

6 9

input

23

output

8 15

input

1000000

output

500000 500000

Note

In the first example, 12 = 4 + 8 and both 4, 8 are composite numbers. You can output "6 6" or "8 4" as well.

In the second example, 15 = 6 + 9. Note that you can't output "1 14" because 1 is not a composite number.

题解

模拟即可。

PS：第一次参加7题3小时的比赛，顿感手速慢的痛苦。

#include<cstdio>#include<cstring>#include<cstdlib>#include<iostream>#include<cmath>#include<algorithm>using namespace std;int n;bool check(int x){    int i;    for(i=2;i<=sqrt(x);i++)       {if(x%i==0) return true;}    return false;}int main(){    scanf("%d",&n);    int i;    for(i=2;i<=n/2;i++)       {if(check(i)&&check(n-i))           {printf("%d %d\n",i,n-i); return 0;}       }    return 0;}