#include <bits/stdc++.h>
using namespace std;
int const N = 312312;
int const INF = 1e9 + 7;
int a[10], b[10], as;
int main() {
  for (int c = 1; c <= 3; c++) {
    cin >> a[c];
  }
  for (int c = 1; c <= 3; c++) {
    cin >> b[c];
  }
  for (int c = 1; c <= 3; c++) {
    if (a[c] >= b[c]) {
      as += (a[c] - b[c]) / 2;
    }
  }
  for (int c = 1; c <= 3; c++) {
    if (a[c] >= b[c]) continue;
    if (a[c] + as >= b[c]) {
      as -= (b[c] - a[c]);
    } else {
      puts("No");
      return 0;
    }
  }
  cout << "Yes";
  return 0;
}
