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