Here you have the first 12 terms of the Fibonacci sequence: F1 1 F2 = 1 F3-2 F4 3 F5- 5 F6-8 F7 - 13 F8 21 Fo- 34 F10 55 F11-89 F12-144 The 12th term, F12, is the first term to contain three digits. Write a PHP function that given an integer value n in input, returns the index of the first term in the Fibonacci sequence to contain n digits. Example: For n-2, it would return 7 For n = 3, it would return 12