local function meld(node1,node2)
    if not node1 then
        return node2
    elseif not node2 then
        return node1
    elseif node1[1]<node2[1] then
        node2[4]=node1[3]
        node1[3]=node2
        return node1
    else
        node1[4]=node2[3]
        node2[3]=node1
        return node2
    end
end

local function pairing(node,stack)
    if node and node[4] then
        return pairing(node[4][4],rawset(meld(node,node[4]),4,stack))
    else
        return stack,node
    end
end

local function meld_pairs(stack,node)
    if stack then
        return meld_pairs(stack[4],meld(stack,node))
    else
        return node
    end
end

local PairingHeap={}

PairingHeap.empty=function(self)
    return not self[1]
end

PairingHeap.push=function(self,key,value)
    self[1]=meld(self[1],{key,value,false,false})
end

PairingHeap.top=function(self)
    return self[1][2]
end

PairingHeap.pop=function(self)
    self[1]=meld_pairs(pairing(self[1][3],false))
end

PairingHeap.new=function()
    return setmetatable({false},{__index=PairingHeap})
end

----------

local n=io.read("*n")
local a={}
for i=1,n do
    a[i]=io.read("*n")
end
local b={}
for i=1,n do
    b[i]=io.read("*n")
end

local min=10^20
for i=0,n-1 do
    local pq=PairingHeap:new()
    for j=1,n do
        pq:push(a[j],{a[j],0})
    end
    for j=1+i,n+i do
        local A=pq:top() pq:pop()
        if j>n then
            A[1]=math.floor((A[1]+b[j%n])/2)
            A[2]=A[2]+1
            pq:push(A[1],A)
        else
            A[1]=math.floor((A[1]+b[j])/2)
            A[2]=A[2]+1
            pq:push(A[1],A)
        end 
    end
    local max=0
    for j=1,n do
        local a=pq:top() pq:pop()
        max=math.max(a[2],max)
    end
    min=math.min(max,min)
end
print(min)