list=[]
i = int(input())
list=[int(a) for a in input().split()]
max=max(list)
while max*i/2 -sum(list)<=0:
max+=1
print(max)115A - Party | 746B - Decoding |
1424G - Years | 1663A - Who Tested |
1073B - Vasya and Books | 195B - After Training |
455A - Boredom | 1099A - Snowball |
1651D - Nearest Excluded Points | 599A - Patrick and Shopping |
237A - Free Cash | 1615B - And It's Non-Zero |
1619E - MEX and Increments | 34B - Sale |
1436A - Reorder | 1363C - Game On Leaves |
1373C - Pluses and Minuses | 1173B - Nauuo and Chess |
318B - Strings of Power | 1625A - Ancient Civilization |
864A - Fair Game | 1663B - Mike's Sequence |
448A - Rewards | 1622A - Construct a Rectangle |
1620A - Equal or Not Equal | 1517A - Sum of 2050 |
620A - Professor GukiZ's Robot | 1342A - Road To Zero |
1520A - Do Not Be Distracted | 352A - Jeff and Digits |