#include <bits/stdc++.h>
using namespace std;
const long long MXN = 1e6 + 1;
const long long MNN = 5e3 + 1;
const long long MOD = 1e9 + 7;
const long long INF = 1e18;
const long double EPS = 1e-9;
long long ans1, ans2;
long long a[MXN], b[MXN];
int main() {
  ios_base::sync_with_stdio(0);
  for (long long i = 1; i <= 3; i++) {
    scanf("%I64d", &a[i]);
  }
  for (long long i = 1; i <= 3; i++) {
    scanf("%I64d", &b[i]);
  }
  for (long long i = 1; i <= 3; i++) {
    if (a[i] >= b[i]) {
      ans1 += (a[i] - b[i]) / 2;
    } else {
      ans2 += b[i] - a[i];
    }
  }
  if (ans2 <= ans1) {
    puts("Yes");
  } else {
    puts("No");
  }
  return 0;
}
