#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  scanf("%d%d", &a, &b);
  ;
  scanf("%d", &c);
  int x, y, z;
  scanf("%d%d", &x, &y);
  ;
  scanf("%d", &z);
  int excess = 0;
  int req = 0;
  if (a > x)
    excess += (a - x) / 2;
  else
    req += (x - a);
  if (b > y)
    excess += (b - y) / 2;
  else
    req += (y - b);
  if (c > z)
    excess += (c - z) / 2;
  else
    req += (z - c);
  if (excess >= req)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
