## Example 1
## arrInt = [5, 3, 6, 1, 12]
## nStart = 3

## Example 2
## arrInt = [1, 2, 4, 3]
## nStart = 1

## Example 3
arrInt = [5, 6, 7]
nStart = 2

nFinal = nStart
while nFinal in arrInt:
    nFinal = nFinal * 2

print (nFinal)