#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c;
  cin >> a >> b >> c;
  int x, y, z;
  cin >> x >> y >> z;
  int aRemaining = 0, bRemaining = 0, cRemaining = 0;
  bool aOk = false, bOk = false, cOk = false;
  if (a >= x) {
    aRemaining = a - x;
    aOk = true;
  }
  if (b >= y) {
    bRemaining = b - y;
    bOk = true;
  }
  if (c >= z) {
    cRemaining = c - z;
    cOk = true;
  }
  int totalBalls = aRemaining / 2 + bRemaining / 2 + cRemaining / 2;
  if (!aOk) {
    if (totalBalls > 0 && x - a <= totalBalls) {
      totalBalls -= x - a;
      aOk = true;
    }
  }
  if (!bOk) {
    if (totalBalls > 0 && y - b <= totalBalls) {
      totalBalls -= y - b;
      bOk = true;
    }
  }
  if (!cOk) {
    if (totalBalls > 0 && z - c <= totalBalls) {
      totalBalls -= z - c;
      cOk = true;
    }
  }
  if (aOk && bOk && cOk) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
