#include<cstdio>

#include<algorithm>

using namespace std;

const int maxn =  + ;

int n, p[maxn], s[maxn], h[maxn];

int main() {

  int T;

  scanf("%d", &T);

  while(T--) {

    scanf("%d", &n);

    for(int i = ; i < n; i++) scanf("%d", &p[i]);

    for(int i = ; i < n; i++) scanf("%d", &s[i]);

    int ans = , level = s[];

    for(int i = ; i < n; i++) {

      if(p[i] > level) level = p[i];

      if(s[i] < level) level = s[i];

      h[i] = level;

    }

    level = s[n-];

    for(int i = n-; i >= ; i--) {

      if(p[i] > level) level = p[i];

      if(s[i] < level) level = s[i];

      ans += min(h[i], level) - p[i];

    }

    printf("%d\n", ans);

  }

  return ;

}