#include <bits/stdc++.h>
using namespace std;
int v[5], d[5];
int main() {
  for (int i = 0; i < 3; i++) {
    scanf("%d", &v[i]);
  }
  for (int i = 0; i < 3; i++) {
    scanf("%d", &d[i]);
  }
  int has = 0;
  for (int i = 0; i < 3; i++) {
    if (v[i] > d[i]) {
      has += (v[i] - d[i]) / 2;
    }
  }
  for (int i = 0; i < 3; i++) {
    int dif = v[i] - d[i];
    if (dif < 0) {
      dif *= -1;
      if (dif <= has) {
        has -= dif;
      } else {
        printf("No\n");
        return 0;
      }
    }
  }
  printf("Yes\n");
}
