Problem A
Blaðra
                                                                Languages
                        
                            
                                                                    en
                                                                    is
                                                            
                        
                                                                
   
      The common element of birthdays and programming contests are the balloons. You have arrived to the 20 year anniversary of Forritunarkeppni Framhaldsskólanna. There you receive a really neat balloon.
OH NO!
You lose your grip on the balloon and it floats upwards. If you find a long stick or a ladder you might be able to reach it and pull it back down.
The balloon was moving when you lost your grip, so it has an initial velocity $v$. Its acceleration is $a$ and you estimate it will take you $t$ seconds to get the equipment to save the balloon. Now you just need to find the distance $d$ that the balloon has traveled. Luckily you learned at school that $d = vt + \frac{1}{2}at^2$. What’s the value of $d$?
Input
The input is one line and consists of three integers $-1\, 000 \leq v \leq 1\, 000$, the initial velocity of the balloon, $-1\, 000 \leq a \leq 1\, 000$, the acceleration of the balloon and $0 \leq t \leq 1\, 000$, the duration of time for which the balloon travels.
Output
Print a single line containing the value $d$. The answer is considered correct if its absolute or relative error from the correct answer is at most $10^{-5}$. This means it does not matter how many significant digits the answer contains as long as its accurate enough.
Scoring
| Group | Points | Constraints | 
| 1 | 100 | No further constraints | 
| Sample Input 1 | Sample Output 1 | 
|---|---|
| 0 3 3 | 13.500000000 | 
| Sample Input 2 | Sample Output 2 | 
|---|---|
| 13 1 6 | 96.000000000 | 
