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# Represent the given number as the sum of two composite numbers

• Difficulty Level : Easy
• Last Updated : 18 Mar, 2021

Given an integer N, the task is to represent N as the sum of two composite integers. There can be multiple ways possible, print any one of them. If it is not possible to represent the number as the sum of two composite numbers then print -1.
Examples:

Input: N = 13
Output: 4 9
4 + 9 = 13 and both 4 and 9 are composite.
Input: N = 18
Output: 4 14

Approach: When N ≤ 11 then only 8 and 10 are the integers which can be represented as the sum of two composite integers i.e. 4 + 4 and 4 + 6 respectively.
When N > 11 then there are two cases:

1. When N is even: N can be represented as 4 + (N – 4) since both are composite.
2. When N is odd: N can be represented as 9 + (N – 9).

Below is the implementation of the above approach:

## C++

 `// C++ implementation of the approach``#include ``using` `namespace` `std;` `// Function to find two composite``// numbers which when added``// give sum as n``void` `findNums(``int` `n)``{` `    ``// Only 8 and 10 can be represented``    ``// as the sum of two composite integers``    ``if` `(n <= 11) {``        ``if` `(n == 8)``            ``cout << ``"4 4"``;``        ``if` `(n == 10)``            ``cout << ``"4 6"``;``        ``else``            ``cout << ``"-1"``;``        ``return``;``    ``}` `    ``// If n is even``    ``if` `(n % 2 == 0)``        ``cout << ``"4 "` `<< (n - 4);` `    ``// If n is odd``    ``else``        ``cout << ``"9 "` `<< (n - 9);``}` `// Driver code``int` `main()``{``    ``int` `n = 13;` `    ``findNums(n);` `    ``return` `0;``}`

## Java

 `// Java implementation of the approach``class` `GFG``{``    ` `// Function to find two composite``// numbers which when added``// give sum as n``static` `void` `findNums(``int` `n)``{` `    ``// Only 8 and 10 can be represented``    ``// as the sum of two composite integers``    ``if` `(n <= ``11``)``    ``{``        ``if` `(n == ``8``)``            ``System.out.print(``"4 4"``);``        ``if` `(n == ``10``)``            ``System.out.print(``"4 6"``);``        ``else``            ``System.out.print(``"-1"``);``        ``return``;``    ``}` `    ``// If n is even``    ``if` `(n % ``2` `== ``0``)``        ``System.out.print(``"4 "` `+ (n - ``4``));` `    ``// If n is odd``    ``else``        ``System.out.print(``"9 "` `+ (n - ``9``));``}` `// Driver code``public` `static` `void` `main(String args[])``{``    ``int` `n = ``13``;` `    ``findNums(n);``}``}` `// This code is contributed by andrew1234`

## Python3

 `# Python3 implementation of the approach` `# Function to find two composite``# numbers which when added``# give sum as n``def` `findNums(n):` `    ``# Only 8 and 10 can be represented``    ``# as the sum of two composite integers``    ``if` `(n <``=` `11``):``        ``if` `(n ``=``=` `8``):``            ``print``(``"4 4"``, end ``=` `" "``)``        ``if` `(n ``=``=` `10``):``            ``print``(``"4 6"``, end ``=` `" "``)``        ``else``:``            ``print``(``"-1"``, end ``=` `" "``)` `    ``# If n is even``    ``if` `(n ``%` `2` `=``=` `0``):``        ``print``(``"4 "``, (n ``-` `4``), end ``=` `" "``)` `    ``# If n is odd``    ``else``:``        ``print``(``"9 "``, n ``-` `9``, end ``=` `" "``)` `# Driver code``n ``=` `13` `findNums(n)` `# This code is contributed by Mohit Kumar`

## C#

 `// C# implementation of the approach``using` `System;` `class` `GFG``{``    ` `    ``// Function to find two composite``    ``// numbers which when added``    ``// give sum as n``    ``static` `void` `findNums(``int` `n)``    ``{``    ` `        ``// Only 8 and 10 can be represented``        ``// as the sum of two composite integers``        ``if` `(n <= 11)``        ``{``            ``if` `(n == 8)``                ``Console.Write(``"4 4"``);``            ``if` `(n == 10)``                ``Console.Write(``"4 6"``);``            ``else``                ``Console.Write(``"-1"``);``            ``return``;``        ``}``    ` `        ``// If n is even``        ``if` `(n % 2 == 0)``            ``Console.Write(``"4 "` `+ (n - 4));``    ` `        ``// If n is odd``        ``else``            ``Console.Write(``"9 "` `+ (n - 9));``    ``}``    ` `    ``// Driver code``    ``public` `static` `void` `Main()``    ``{``        ``int` `n = 13;``    ` `        ``findNums(n);``    ``}``}` `// This code is contributed by AnkitRai01`

## Javascript

 ``
Output:
`9 4`

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