There are n colorful tiles arranged in a line T$1,$ T$2,...,$ Tn$.$ Each tile is colored with either Red,

Green or Blue color. T$1$ is Red.

A frog, which is currently on T$1,$ is trying to reach Tn$.$ However, the jumps of the frog are restricted as

follows:

$1.$ If it is currently on tile i$,$ then it can only jump to a tile j where j $>$ i$.$

$2.$ The sequence of the color of the tiles on which it jumps must be in the following specific order: Red,

Green, Blue, Red, Green, Blue, $....$

The jumps can be arbitrarily long. However, longer jumps are harder: a jump of length k costs k $$ k energy.

Note that the final tile Tn also has some color and thus the frog must reach it in a corresponding step.

Given an input x in $\{$Red$,$ Green, Blue$\}$

n$,$ i$.$e$.,$ the sequence of the colors of the tiles, design an algorithm

that returns the smallest possible total cost of doing so$.$ If it is impossible to reach the final tile, return $-1.$