#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << std::endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
int main() {
  ios_base::sync_with_stdio(false);
  int a, b, c;
  cin >> a >> b >> c;
  int x, y, z;
  cin >> x >> y >> z;
  int reqd = 0, spare = 0;
  if (a >= x)
    spare += (a - x) / 2;
  else
    reqd += x - a;
  if (b >= y)
    spare += (b - y) / 2;
  else
    reqd += y - b;
  if (c >= z)
    spare += (c - z) / 2;
  else
    reqd += z - c;
  if (reqd <= spare)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
