4919: Rat Kwesh and Cheese

Wet Shark asked Rat Kwesh to generate three positive real numbers x, y and z, from 0.1 to 200.0, inclusive. Wet Krash wants to impress Wet Shark, so all generated numbers will have exactly one digit after the decimal point.
Wet Shark knows Rat Kwesh will want a lot of cheese. So he will give the Rat an opportunity to earn a lot of cheese. He will hand the three numbers x, y and z to Rat Kwesh, and Rat Kwesh will pick one of the these twelve options:

1. a₁=x^yz;
2. a₂=x^zy;
3. a₃=(x^y)^z;
4. a₄=(x^z)^y;
5. a₅=y^xz;
6. a₆=y^zx;
7. a₇=(y^x)^z;
8. a₈=(y^z)^x;
9. a₉=z^xy;
10. a₁₀=z^yx;
11. a₁₁=(z^x)^y;
12. a₁₂=(z^y)^x.

Let m be the maximum of all the a_i, and c be the smallest index (from 1 to 12) such that a_c=m. Rat's goal is to find that c, and he asks you to help him. Rat Kwesh wants to see how much cheese he gets, so he you will have to print the expression corresponding to that a_c.

1.1 3.4 2.5

z^y^x

2.0 2.0 2.0

x^y^z

1.9 1.8 1.7

(x^y)^z