#include <bits/stdc++.h>
using namespace std;
int INF = 0x3f3f3f3f;
int mod = 1e9 + 7;
int MAXN = 12345;
double eps = 1e-7;
int dcmp(double a, double b) { return (a - b < eps) ? -1 : (a - b >= eps); }
int main(int argc, char **argv) {
  ios::sync_with_stdio(false);
  int n, m;
  scanf("%d", &n);
  for (int i = 0; i < n; ++i) scanf("%d", &m);
  int ans = 0;
  for (int i = 0; i < n; ++i) {
    scanf("%d", &m);
    ans += m;
  }
  for (int i = 0; i < n - 1; ++i) {
    scanf("%d", &m);
    if (i) ans += m;
  }
  printf("%d\n", ans);
  return 0;
}
