#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<int> A, B;
  int x;
  for (int i = 0; i < 3; i++) {
    cin >> x;
    A.push_back(x);
  }
  int medBall = 0, reqBall = 0;
  for (int i = 0; i < 3; i++) {
    cin >> x;
    B.push_back(x);
  }
  for (int i = 0; i < 3; i++) {
    if (A[i] >= B[i]) {
      int y = (A[i] - B[i]) / 2;
      medBall += y;
    } else
      reqBall += B[i] - A[i];
  }
  if (reqBall <= medBall)
    printf("Yes\n");
  else
    printf("No\n");
  return 0;
}
