uva1442

#include<cstdio>
#include<algorithm>
#define maxn 1000000+10

using namespace std;
int s[maxn],p[maxn],h1[maxn],h2[maxn],n;
int solve()
{
    int cnt=0,tmp1=s[n-1],tmp2=s[0];
    for(int i=n-1; i>=0; i--)
    {
        if(tmp1<p[i])tmp1=p[i];
        if(tmp1>s[i])tmp1=s[i];
        h1[i]=tmp1;
    }
    for(int i=0; i<n; i++)
    {
        if(tmp2<p[i])tmp2=p[i];
        if(tmp2>s[i])tmp2=s[i];
        h2[i]=tmp2;
    }
    for(int i=0; i<n; i++)
    {
        h1[i]=min(h1[i],h2[i]);
        cnt+=h1[i]-p[i];
    }
    return cnt;
}
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&n);
        for(int i=0; i<n; i++)
            scanf("%d",&p[i]);
        for(int i=0; i<n; i++)
            scanf("%d",&s[i]);
        printf("%d\n",solve());
    }
    return 0;
}