#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, x, y, z;
  cin >> a >> b >> c >> x >> y >> z;
  int s = 0;
  int n = 0;
  if (a >= x) {
    s += (a - x) / 2;
  } else {
    n += x - a;
  }
  if (b >= y) {
    s += (b - y) / 2;
  } else {
    n += y - b;
  }
  if (c >= z) {
    s += (c - z) / 2;
  } else {
    n += z - c;
  }
  if (s >= n) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
