#include <bits/stdc++.h>
using namespace std;
const int N = 1e6+5;
const int inf=1e9;
#define  PII pair<int,int>
int a[N],b[N];
PII c[N];
int p_a[N],p_b[N];
int tot=inf;
int n;
int now=0;
bool flag=0;
void dfs()
{
//    cout<<tot<<"\n";
    vector<int>aa(n+1);
    for(int i=1;i<=n;i++) aa[i]=a[i];
    bool ok=true;
    int cntt=0;
    for(int i=2;i<=n;i++){
        int x=a[i]/2-a[i-1]/2;
        if(x<p_b[i]){
            ok=false;
        }else if(x==p_b[i]&&a[1]/2<=b[1]){
            cntt++;
        }
    }
    if(cntt==n-1){
        flag=1;
        tot=min(tot,now+1+b[1]-a[1]/2);
        return;
    }
    if(ok){
        for(int i=1;i<=n;i++){
            a[i]/=2;
        }
        now++;
        dfs();
        now--;
        for(int i=1;i<=n;i++){
            a[i]=aa[i];
        }
    }
    ok=true;
    cntt=0;
    for(int i=2;i<=n;i++){
        int x=(a[i]+1)/2-(a[i-1]+1)/2;
        if(x<p_b[i]){
            ok=false;
        }else if(x==p_b[i]&&(a[1]+1)/2<=b[1]){
            cntt++;
        }
    }
    if(cntt==n-1){
        flag=1;
        tot=min(tot,now+2+b[1]-(a[1]+1)/2);
        return;
    }
    if(ok){
        for(int i=1;i<=n;i++){
            a[i]=(a[i]+1)/2;
        }
        now+=2;
        dfs();
        now-=2;
        for(int i=1;i<=n;i++){
            a[i]=aa[i];
        }
    }

}
bool solve() {
    cin>>n;
    for(int i=1;i<=n;i++ )cin>>a[i];
    for(int i=1;i<=n;i++){
        cin>>b[i];
        c[i]={a[i],b[i]};
    }
    sort(c+1,c+1+n);
    for(int i=2;i<=n;i++){
        if(c[i].second<c[i-1].second) return false;
    }
    p_a[1]=c[1].first,a[1]=c[1].first,b[1]=c[1].second;
    for(int i=2;i<=n;i++){
        a[i]=c[i].first,b[i]=c[i].second;
        p_a[i]=c[i].first;
        p_b[i]=c[i].second-c[i-1].second;
    }
    dfs();
    return true;

}
int main() {
    solve();
    if(flag){
        cout<<tot<<'\n';
    }else{
        cout<<-1<<"\n";
    }
}