fix(guide): simplify directory structure

guide/english/certifications/coding-interview-prep/project-euler/problem-3-largest-prime-factor/index.md

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+---
+title: Largest prime factor
+---
+## Problem 3: Largest prime factor
+
+### Method:
+- To find the largest prime factor of a number, we start from the smallest prime factor 2 and divide the number with it.
+- If the remainder is 0 that means the number is divisible by that prime number, we keep dividing the number by same prime number until that number is no more divisible by that prime number. 
+- After that, we incrememnt the prime factor by 1 and repeat this process till the number becomes 1.
+
+
+### Solution:
+```js
+function largestPrimeFactor(number) {
+  let prime = 2, max = 1;
+  while (prime <= number){
+    if (number % prime == 0) {
+      max = prime;
+      number = number/prime;
+    }
+    else prime++; //Only increment the prime number if the number isn't divisible by it
+  }
+  return max;
+}
+```
+- [Run Code](https://repl.it/@ezioda004/Problem-3-Largest-prime-factor)
+### Resources:
+
+- [Wikipedia](https://en.wikipedia.org/wiki/Prime_number)