Huh, is that it? Slightly disappointed, you boot up the game and click on the new gamemode. It says "Colored platforms".

There are $n$ platforms, numbered from $1$ to $n$, placed one after another. There are $m$ colors available in the game, numbered from $1$ to $m$. The $i$-th platform is colored $c_i$.

You start on the platform $1$ and want to reach platform $n$. In one move, you can jump from some platform $i$ to platforms $i + 1$ or $i + 2$.

All platforms are initially deactivated (including platforms $1$ and $n$). For each color $j$, you can pay $x_j$ coins to activate all platforms of that color.

You want to activate some platforms so that you could start on an activated platform $1$, jump through some activated platforms and reach an activated platform $n$.

What's the smallest amount of coins you can spend to achieve that?