#include <bits/stdc++.h>
using namespace std;
inline bool cmp(const pair<int, int> &p, const pair<int, int> &q) {
  return (p.first == q.first) ? p.second > q.second : p.first > q.first;
}
int main() {
  int a, b, c;
  int x, y, z;
  scanf("%d %d %d", &a, &b, &c);
  scanf("%d %d %d", &x, &y, &z);
  int extra = 0, remain = 0;
  if (a >= x) {
    extra = (a - x) / 2;
  } else {
    remain = x - a;
  }
  if (b >= y) {
    extra += (b - y) / 2;
  } else {
    remain += y - b;
  }
  if (c >= z) {
    extra += (c - z) / 2;
  } else {
    remain += z - c;
  }
  if (remain > extra)
    printf("No\n");
  else
    printf("Yes\n");
  return 0;
}
