n = read_line.to_i
a = read_line.split.map(&.to_i)
b = read_line.split.map(&.to_i)
c = read_line.split.map(&.to_i)
s1 = a.sum {|i| b[i-1]}
s2 = n.pred.times.sum {|i| a[i]+1 == a[i+1] ? c[i-1] : 0}
puts s1 + s2