As the friends traversed a particularly whimsical clearing filled with chattering squirrels, they encountered a rather anxious-looking critter. "Oh dear, oh dear!" it squeaked, clutching a tiny abacus. "I've scattered my special enchanted nuts all across this clearing! Each nut holds a unique magical energy, represented by a number. I need to find two nuts whose combined energy is... odd! And if I find such a pair, I want the largest possible odd sum!"
Sam07a, intrigued by the squirrel's dilemma, recognized it as a peculiar challenge. Omar, always observant, started noting down the energy values of the nuts they saw scattered on the ground. Abd-Elmohaymen, convinced the squirrel was secretly a forest spirit, felt compelled to help.
The squirrel explained that it had already gathered N nuts, and it knew the energy value $$$A_i$$$ of each one. Their task was to help the squirrel determine if there existed any pair of different nuts whose energy values, when added together, resulted in an odd sum. If such a pair existed, they needed to find the maximum possible odd sum that could be formed. If no such pair could be found, the squirrel would be heartbroken, and they'd have to tell it $$$-1$$$.
Help them sort through the squirrel's scattered nuts and find the largest possible odd sum.
The first line contains a single integer $$$N$$$ $$$(2\leq N \leq 2 \cdot{10 ^ 5} )$$$ — the number of enchanted nuts.
The following line contains $$$n$$$ integers $$$A_i(1 \leq A_i \leq 2 \cdot{10 ^ 5})$$$ representing the energy value of each nut.
Print a single integer — the maximum possible odd sum of two elements, or $$$-1$$$ if no such pair exists.
63 5 6 1 8 10
15
