import os
import sys

n,m=map(int,input().split())
nums=list(map(int,input().split()))
dnums=list(map(int,input().split()))

# 特殊
ydata=[]
# 不特殊
ndata=0

for x in range(1,n+1):
    if x in dnums:
        ydata.append(nums[x-1])
    else:
        ndata+=nums[x-1]

# print(ydata,ndata)
ydata.sort(reverse=True)
for cho in ydata:
    if ndata>cho:
        ndata+=ndata
    else:
        ndata+=cho
print(ndata)